Neprilysin inhibitors

ABSTRACT

In one aspect, the invention relates to compounds having the formula I: 
                         
where R 1 -R 6  are as defined in the specification, or a pharmaceutically acceptable salt thereof. These compounds have neprilysin inhibition activity. In another aspect, the invention relates to pharmaceutical compositions comprising these compounds; methods of using these compounds; and processes and intermediates for preparing these compounds.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No.15/419,217, filed Jan. 30, 2017, now allowed; which is a divisional ofU.S. application Ser. No. 14/608,686, filed Jan. 29, 2015, now U.S. Pat.No. 9,593,110; which application claims the benefit of U.S. ProvisionalApplication No. 61/933,406, filed on Jan. 30, 2014, and 62/016,742,filed on Jun. 6, 2014; the entire disclosures of which are incorporatedherein by reference.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to novel compounds havingneprilysin-inhibition activity. The invention also relates topharmaceutical compositions comprising these compounds, processes andintermediates for preparing these compounds and methods of using thesecompounds to treat diseases such as hypertension, heart failure,pulmonary hypertension, and renal disease.

State of the Art

Neprilysin (neutral endopeptidase, EC 3.4.24.11) (NEP), is anendothelial membrane bound Zn²⁺metallopeptidase found in many organs andtissues, including the brain, kidneys, lungs, gastrointestinal tract,heart, and the peripheral vasculature. NEP degrades and inactivates anumber of endogenous peptides, such as enkephalins, circulatingbradykinin, angiotensin peptides, and natriuretic peptides, the latterof which have several effects including, for example, vasodilation andnatriuresis/diuresis, as well as inhibition of cardiac hypertrophy andventricular fibrosis. Thus, NEP plays an important role in bloodpressure homeostasis and cardiovascular health.

NEP inhibitors, such as thiorphan, candoxatril, and candoxatrilat, havebeen studied as potential therapeutics. Compounds that inhibit both NEPand angiotensin-I converting enzyme (ACE) are also known, and includeomapatrilat, gempatrilat, and sampatrilat. Referred to as vasopeptidaseinhibitors, this latter class of compounds is described in Robl et al.(1999) Exp. Opin. Ther. Patents 9(12): 1665-1677.

In spite of these compounds however, there remains a need for NEPinhibitors that have improved potency, different metabolic and cleavageproperties, and/or having improved oral absorption. This invention isdirected to that need.

SUMMARY OF THE INVENTION

The present invention provides novel compounds that have been found topossess neprilysin (NEP) enzyme inhibition activity. Accordingly,compounds of the invention are expected to be useful and advantageous astherapeutic agents for treating conditions such as hypertension andheart failure.

One aspect of the invention relates to a compound of formula I:

where:

R¹ is H, —C₁₋₈alkyl, —CH(CH₃)OC(O)—O-cyclohexyl, —(CH₂)₂-morpholinyl, or—CH₂-5-methyl-[1,3]dioxol-2-one;

R² is —CH₂—O—R²⁰, —C₀₋₁alkylene-NHC(O)—R²¹, —C₀₋₃alkylene-NR²²R²³,—CH₂—R²⁴, oxetane, 2-pyridine, 3-pyridine, thiophene, tetrahydropyran,or piperidine and having H or —C(O)CH₃ on the nitrogen, saidtetrahydropyran and piperidine being attached at the 4-position; whereR²⁰ is —C₁₋₆alkyl, —CH₂NR²⁷CHR²⁸—, —C₂₋₃alkylene-OH, or—C₂₋₃alkylene-NR²⁹R³⁰; R²¹ is —C₁₋₆alkyl, —O—C₁₋₆alkyl,—C₀₋₆alkylene-NR²⁵R²⁵, —CH(NH₂)—R²⁶, —C₁₋₄alkylene-NHC(O)O—C₁₋₆alkyl,—OCH(CH₃)OC(O)CH(CH₃)₂, or pyrrolidine attached at a carbon atom; R²² isH or —C₁₋₆alkyl; R²³ is H, —C₁₋₆alkyl, —C₁₋₆alkyl substituted with 1 to6 fluoro atoms, —SO₂—C₁₋₆alkyl, —CH₂OC(O)—C₁₋₆alkyl, —C₂₋₄alkylene-OH,—C₂₋₄alkylene-O—CH₃, or cyclopropyl optionally substituted with one ortwo R³¹ groups; or R²² and R²³ are taken together to form—(CH₂)₂—O—(CH₂)₂—, a 2-oxa-6-aza-spiro[3.3]heptane ring, or an azetidinering optionally substituted with one or two R³¹ groups; R²⁴ is —CH₂OH,—CN, —C(O)NH₂, triazole or imidazole attached at a nitrogen atom, oroxadiazolone or tetrazole attached at the carbon atom; each R²⁵ isindependently H or —CH₃; R²⁶ is —C₁₋₄alkylene-NH₂, —CH₂OH, or benzyl;R²⁷ is H, —C₁₋₆alkyl, —C₁₋₆alkyl substituted with 1 to 6 fluoro atoms,—(CH₂)₂OH, or —(CH₂)₂OC₁₋₆alkyl; R²⁸ is H, —C₁₋₆alkyl, —C₁₋₂alkylene-OH,or —C₁₋₂alkylene-OC₁₋₆alkyl; R²⁹ and R³⁰ are independently H,—C₁₋₆alkyl, —C₁₋₆alkyl substituted with 1 to 6 fluoro atoms, —(CH₂)₂OH,or —(CH₂)₂OC₁₋₆alkyl; or R²⁹ and R³⁰ are taken together to form—CH₂—CH₂—CH₂—; and each R³¹ is independently halo, —C₁₋₆alkyl,—C₀₋₂alkylene-OH, —C₀₋₂alkylene-OC₁₋₆alkyl, —CN, or —CONH₂;

R³, R⁴ and R⁵ are independently H or halo;

R⁶ is a heterocycle selected from the group consisting of3H-oxazol-2-one, [1,2,4]oxadiazol-5-one, [1,2,3,5]oxatriazole,dihydro-[1,2,4]triazol-3-one, [1,2,4]triazolo[1,5-a]pyridine, triazole,pyrazole, imidazole, oxazole, isoxazole, isothiazole, pyridine,oxadiazole, and pyrimidine; the heterocycle is attached at a carbonatom; and each nitrogen atom in the heterocycle is unsubstituted orsubstituted with an R⁶⁰ group selected from the group consisting of —OH,—(CH₂)₂OH, —C₀₋₂alkylene-O—C₁₋₆alkyl, —C₁₋₆alkyl, —CHF₂, —CF₃, andphenyl; and each carbon atom in the heterocycle is unsubstituted orsubstituted with an R⁶¹ group independently selected from the groupconsisting of halo, —OH, —C₁₋₆alkyl, —C₀₋₂alkylene-O—C₁₋₆alkyl,—C(O)CH₃, —C(O)NH(CH₃), —C(O)N(CH₃)₂, —C₃₋₆cycloalkyl, —CF₃, —CH₂SO₂CH₃,—NH₂, —CH₂NH₂, —CH₂N(CH₃)₂, pyrazine, and phenyl substituted with methylor halo;

or a pharmaceutically acceptable salt thereof.

Another aspect of the invention relates to pharmaceutical compositionscomprising a pharmaceutically acceptable carrier and a compound of theinvention. Such compositions may optionally contain other therapeuticagents.

Compounds of the invention possess NEP enzyme inhibition activity, andare therefore expected to be useful as therapeutic agents for treatingpatients suffering from a disease or disorder that is treated byinhibiting the NEP enzyme or by increasing the levels of its peptidesubstrates. Thus, one aspect of the invention relates to a method oftreating patients suffering from a disease or disorder that is treatedby inhibiting the NEP enzyme, comprising administering to a patient atherapeutically effective amount of a compound of the invention. Anotheraspect of the invention relates to a method of treating hypertension,heart failure, or renal disease, comprising administering to a patient atherapeutically effective amount of a compound of the invention. Stillanother aspect of the invention relates to a method for inhibiting a NEPenzyme in a mammal comprising administering to the mammal, a NEPenzyme-inhibiting amount of a compound of the invention.

Since compounds of the invention possess NEP inhibition activity, theyare also useful as research tools. Accordingly, one aspect of theinvention relates to a method of using a compound of the invention as aresearch tool, the method comprising conducting a biological assay usinga compound of the invention. Compounds of the invention can also be usedto evaluate new chemical compounds. Thus another aspect of the inventionrelates to a method of evaluating a test compound in a biological assay,comprising: (a) conducting a biological assay with a test compound toprovide a first assay value; (b) conducting the biological assay with acompound of the invention to provide a second assay value; wherein step(a) is conducted either before, after or concurrently with step (b); and(c) comparing the first assay value from step (a) with the second assayvalue from step (b). Exemplary biological assays include a NEP enzymeinhibition assay. Still another aspect of the invention relates to amethod of studying a biological system or sample comprising a NEPenzyme, the method comprising: (a) contacting the biological system orsample with a compound of the invention; and (b) determining the effectscaused by the compound on the biological system or sample.

Yet another aspect of the invention relates to processes andintermediates useful for preparing compounds of the invention.Accordingly, another aspect of the invention relates to a process ofpreparing compounds of formula I, comprising the step of coupling acompound of formula 1 with a compound of formula 2:

to produce a compound of formula I; where P¹ is H or an amino-protectinggroup selected from the group consisting of t-butoxycarbonyl, trityl,benzyloxycarbonyl, 9-fluorenylmethoxycarbonyl, formyl, trimethylsilyl,and t-butyldimethylsilyl; and where the process further comprisesdeprotecting the compound of formula 1 when P¹ is an amino protectinggroup; and where R¹-R⁶ are as defined for formula I. In other aspects,the invention relates to products prepared by any of the processesdescribed herein, as well as novel intermediates used in such process.In one aspect of the invention novel intermediates have formula 1, or asalt thereof, as defined herein.

Yet another aspect of the invention relates to the use of a compound offormula I or a pharmaceutically acceptable salt thereof, for themanufacture of a medicament, especially for the manufacture of amedicament useful for treating hypertension, heart failure, or renaldisease. Another aspect of the invention relates to use of a compound ofthe invention for inhibiting a NEP enzyme in a mammal. Still anotheraspect of the invention relates to the use of a compound of theinvention as a research tool. Other aspects and embodiments of theinvention are disclosed herein.

DETAILED DESCRIPTION OF THE INVENTION

When describing the compounds, compositions, methods and processes ofthe invention, the following terms have the following meanings unlessotherwise indicated. Additionally, as used herein, the singular forms“a,” “an,” and “the” include the corresponding plural forms unless thecontext of use clearly dictates otherwise. The terms “comprising”,“including,” and “having” are intended to be inclusive and mean thatthere may be additional elements other than the listed elements. Allnumbers expressing quantities of ingredients, properties such asmolecular weight, reaction conditions, and so forth used herein are tobe understood as being modified in all instances by the term “about,”unless otherwise indicated. Accordingly, the numbers set forth hereinare approximations that may vary depending upon the desired propertiessought to be obtained by the present invention. At least, and not as anattempt to limit the application of the doctrine of equivalents to thescope of the claims, each number should at least be construed in lightof the reported significant digits and by applying ordinary roundingtechniques.

The term “alkyl” means a monovalent saturated hydrocarbon group whichmay be linear or branched. Unless otherwise defined, such alkyl groupstypically contain from 1 to 10 carbon atoms and include, for example,—C₁₋₆alkyl, meaning an alkyl group having from 1 to 6 carbon atoms wherethe carbon atoms are in any acceptable configuration. Representativealkyl groups include, by way of example, methyl, ethyl, n-propyl,isopropyl, n-butyl, s-butyl, isobutyl, t-butyl, n-pentyl, n-hexyl, andthe like.

The term “alkylene” means a divalent saturated hydrocarbon group thatmay be linear or branched. Unless otherwise defined, such alkylenegroups typically contain from 0 to 10 carbon atoms and include, forexample, —C₀₋₁alkylene-, —C₀₋₂alkylene-, —C₁₋₂alkylene-, —C₁₋₆alkylene-,and so form. Representative alkylene groups include, by way of example,methylene, ethane-1,2-diyl (“ethylene”), propane-1,2-diyl,propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl and the like. It isunderstood that when the alkylene term include zero carbons such as—C₀₋₂alkylene-, such terms are intended to include the absence of carbonatoms, that is, the alkylene group is not present except for a covalentbond attaching the groups separated by the alkylene term.

The term “cycloalkyl” means a monovalent saturated carbocyclichydrocarbon group. Unless otherwise defined, such cycloalkyl groupstypically contain from 3 to 10 carbon atoms and include, for example,—C₃₋₅cycloalkyl, —C₃₋₆cycloalkyl and —C₃₋₇cycloalkyl. Representativecycloalkyl groups include, by way of example, cyclopropyl, cyclobutyl,cyclopentyl, cyclohexyl and the like.

The term “halo” means fluoro, chloro, bromo and iodo.

The term “heterocycle” is intended to include monovalent unsaturated(aromatic) heterocycles having a single ring or two fused rings as wellas monovalent saturated and partially unsaturated groups having a singlering or multiple condensed rings. The heterocycle ring can contain from3 to 15 total ring atoms, of which 1 to 14 are ring carbon atoms (e.g.,—C₁₋₇heterocycle, —C₃₋₅heterocycle, —C₂₋₆heterocycle, —C₃₋₁₂heterocycle,—C₅₋₉heterocycle, —C₁₋₉heterocycle, —C₁₋₁₁heterocycle, and—C₁₋₁₄heterocyle), and 1 to 4 are ring heteroatoms selected fromnitrogen, oxygen or sulfur. Typically, however, the heterocycle ringcontains from 3 to 10 total ring atoms, of which 1 to 9 are ring carbonatoms, and 1 to 4 are ring heteroatoms. Exemplary heterocycles include,for example, —C₁₋₉heterocycle, —C₃₋₅heterocycle, —C₂₋₆heterocycle,—C₃₋₁₂heterocycle, —C₅₋₉heterocycle, —C₁₋₉heterocycle,—C₁₋₁₁heterocycle, and —C₁₋₁₄heterocyle. Exemplary heterocycles include3H-oxazol-2-one, 4H-[1,2,4]oxadiazol-5-one,dihydro-[1,2,4]triazol-3-one, [1,2,3,5]oxatriazole, triazole, pyrazole,oxazole, isoxazole, isothiazole, pyridine, oxadiazole, and pyrimidine.

When a heterocycle is described as being “attached at a carbon atom,” itmeans that the point of attachment is at any available carbon ring atom.Examples of heterocycles attached at a carbon atom are the triazolerings illustrated below:

The term “optionally substituted” means that group in question may beunsubstituted or it may be substituted one or several times, such as 1to 3 times, or 1 to 5 times, or 1 to 8 times. For example, a heterocyclethat is “optionally substituted” with one or two halo or hydroxylgroups, may be unsubstituted, or it may contain one halo group, onehydroxyl group, two halo groups, two hydroxyl group, or one halo groupand one hydroxyl group. Generally, such groups can be positioned on anyavailable atom provided that the normal valency of the designated atomis not exceeded and that the substitution results in a stable moiety.Such groups may be specified as being on an available nitrogen atom oran available carbon atom.

When a nitrogen atom in a heterocycle is described as being“substituted,” it means that the hydrogen atom on the nitrogen isreplaced with a selected moiety, provided that the normal valency of thenitrogen is not exceeded, and that the substitution results in a stablering. Similarly, when a nitrogen atom in a heterocycle is described asbeing “unsubstituted,” it means that a hydrogen atom is on the nitrogenor the valency of the nitrogen has already been met without substitution(for example the nitrogen atom in a pyridine ring). For example,triazole has three nitrogen atoms present. The first triazole depictedhas all unsubstituted nitrogen atoms since two nitrogen atoms have theirvalency met without substitution and one nitrogen atom has a hydrogenpresent. On the other hand, the second triazole depicted is substitutedon the nitrogen atom with an R⁶⁰ group:

There are instances where the heterocycle will not be substituted withan R⁶⁰ group. For example, pyridine has one nitrogen atom present, butthe valency of the nitrogen atom is met without substitution:

Similarly, triazole has two carbon atoms present, with one forming thepoint of attachment to the remainder of the compound. The first triazolehas an “unsubstituted” carbon atom, while the second triazole issubstituted on the carbon atom with an R⁶¹ group, and the third triazoleis substituted on the carbon atom with an R⁶¹ group and on the nitrogenatom with an R⁶⁰ group:

When a carbon atom in a heterocycle is described as being “substituted,”it means that the hydrogen atom on the carbon is replaced with aselected moiety, provided that the normal valency of the carbon is notexceeded, and that the substitution results in a stable ring. Similarly,when a carbon atom in a heterocycle is described as being“unsubstituted,” it means that a hydrogen atom is on the carbon atom orits valency has already been met without substitution (for example theoxo group on 4H-[1,2,4]oxadiazol-5-one). For example, pyrazole has threecarbon atoms present, with one forming the point of attachment to theremainder of the compound, such that it is not available forsubstitution. The first pyrazole has two “unsubstituted” carbon atoms,while the second pyrazole has a first “unsubstituted” carbon atom and asecond carbon atom that is substituted with an R⁶¹ group, the thirdpyrazole is substituted on both carbon atoms with an R⁶¹ group (whichmay be the same or different; depicted at R^(61a) and R^(61b)), and thefourth pyrazole is substituted on both carbon atoms with an R⁶¹ group:

There are instances where the heterocycle will not be substituted withan R⁶¹ group. For example, although 4H-[1,2,4]oxadiazol-5-one has twocarbon atoms present, one carbon atom forms the point of attachment tothe remainder of the compound and the other carbon atom is alreadysubstituted with an oxo group and so is not available for substitutionwith an R⁶¹ group:

Similarly, [1,2,3,5]oxatriazole has one carbon atom present, but itforms the point of attachment to the remainder of the compound:

As used herein, the phrase “of the formula” or “having the formula” or“having the structure” is not intended to be limiting and is used in thesame way that the term “comprising” is commonly used. For example, ifone structure is depicted, it is understood that all stereoisomer andtautomer forms are encompassed, unless stated otherwise.

The term “pharmaceutically acceptable” refers to a material that is notbiologically or otherwise unacceptable when used in the invention. Forexample, the term “pharmaceutically acceptable carrier” refers to amaterial that can be incorporated into a composition and administered toa patient without causing unacceptable biological effects or interactingin an unacceptable manner with other components of the composition. Suchpharmaceutically acceptable materials typically have met the requiredstandards of toxicological and manufacturing testing, and include thosematerials identified as suitable inactive ingredients by the U.S. Foodand Drug administration.

The term “pharmaceutically acceptable salt” means a salt prepared from abase or an acid which is acceptable for administration to a patient,such as a mammal (for example, salts having acceptable mammalian safetyfor a given dosage regime). However, it is understood that the saltscovered by the invention are not required to be pharmaceuticallyacceptable salts, such as salts of intermediate compounds that are notintended for administration to a patient. Pharmaceutically acceptablesalts can be derived from pharmaceutically acceptable inorganic ororganic bases and from pharmaceutically acceptable inorganic or organicacids. In addition, when a compound of formula I contains both a basicmoiety, such as an amine, pyridine or imidazole, and an acidic moietysuch as a carboxylic acid or tetrazole, zwitterions may be formed andare included within the term “salt” as used herein. Salts derived frompharmaceutically acceptable inorganic bases include ammonium, calcium,copper, ferric, ferrous, lithium, magnesium, manganic, manganous,potassium, sodium, and zinc salts, and the like. Salts derived frompharmaceutically acceptable organic bases include salts of primary,secondary and tertiary amines, including substituted amines, cyclicamines, naturally-occurring amines and the like, such as arginine,betaine, caffeine, choline, N,N′-dibenzylethylenediamine, diethylamine,2-diethylaminoethanol, 2-dimethylaminoethanol, ethanolamine,ethylenediamine, N-ethylmorpholine, N-ethylpiperidine, glucamine,glucosamine, histidine, hydrabamine, isopropylamine, lysine,methylglucamine, morpholine, piperazine, piperadine, polyamine resins,procaine, purines, theobromine, triethylamine, trimethylamine,tripropylamine, tromethamine and the like. Salts derived frompharmaceutically acceptable inorganic acids include salts of boric,carbonic, hydrohalic (hydrobromic, hydrochloric, hydrofluoric orhydroiodic), nitric, phosphoric, sulfamic and sulfuric acids. Saltsderived from pharmaceutically acceptable organic acids include salts ofaliphatic hydroxyl acids (for example, citric, gluconic, glycolic,lactic, lactobionic, malic, and tartaric acids), aliphaticmonocarboxylic acids (for example, acetic, butyric, formic, propionicand trifluoroacetic acids), amino acids (for example, aspartic andglutamic acids), aromatic carboxylic acids (for example, benzoic,p-chlorobenzoic, diphenylacetic, gentisic, hippuric, and triphenylaceticacids), aromatic hydroxyl acids (for example, o-hydroxybenzoic,p-hydroxybenzoic, 1-hydroxynaphthalene-2-carboxylic and3-hydroxynaphthalene-2-carboxylic acids), ascorbic, dicarboxylic acids(for example, fumaric, maleic, oxalic and succinic acids), glucoronic,mandelic, mucic, nicotinic, orotic, pamoic, pantothenic, sulfonic acids(for example, benzenesulfonic, camphosulfonic, edisylic, ethanesulfonic,isethionic, methanesulfonic, naphthalenesulfonic,naphthalene-1,5-disulfonic, naphthalene-2,6-disulfonic andp-toluenesulfonic acids), xinafoic acid, and the like.

The term “therapeutically effective amount” means an amount sufficientto effect treatment when administered to a patient in need thereof, thatis, the amount of drug needed to obtain the desired therapeutic effect.For example, a therapeutically effective amount for treatinghypertension is an amount of compound needed to, for example, reduce,suppress, eliminate, or prevent the symptoms of hypertension, or totreat the underlying cause of hypertension. In one embodiment, atherapeutically effective amount is that amount of drug needed to reduceblood pressure or the amount of drug needed to maintain normal bloodpressure. On the other hand, the term “effective amount” means an amountsufficient to obtain a desired result, which may not necessarily be atherapeutic result. For example, when studying a system comprising a NEPenzyme, an “effective amount” may be the amount needed to inhibit theenzyme.

The term “treating” or “treatment” as used herein means the treating ortreatment of a disease or medical condition (such as hypertension) in apatient, such as a mammal (particularly a human) that includes one ormore of the following: (a) preventing the disease or medical conditionfrom occurring, i.e., preventing the reoccurrence of the disease ormedical condition or prophylactic treatment of a patient that ispre-disposed to the disease or medical condition; (b) ameliorating thedisease or medical condition, i.e., eliminating or causing regression ofthe disease or medical condition in a patient; (c) suppressing thedisease or medical condition, i.e., slowing or arresting the developmentof the disease or medical condition in a patient; or (d) alleviating thesymptoms of the disease or medical condition in a patient. For example,the term “treating hypertension” would include preventing hypertensionfrom occurring, ameliorating hypertension, suppressing hypertension, andalleviating the symptoms of hypertension (for example, lowering bloodpressure). The term “patient” is intended to include those mammals, suchas humans, that are in need of treatment or disease prevention or thatare presently being treated for disease prevention or treatment of aspecific disease or medical condition, as well as test subjects in whichthe crystalline compound is being evaluated or being used in an assay,for example an animal model.

All other terms used herein are intended to have their ordinary meaningas understood by those of ordinary skill in the art to which theypertain.

In one aspect, the invention relates to compounds of formula I:

or a pharmaceutically acceptable salt thereof.

As used herein, the term “compound of the invention” includes allcompounds encompassed by formula I and species thereof. Similarly,reference to compound of a given formula is intended to include allspecies. In addition, the compounds of the invention may also containseveral basic or acidic groups (for example, amino or carboxyl groups)and therefore, such compounds can exist as a free base, free acid, or invarious salt forms. All such salt forms are included within the scope ofthe invention. Furthermore, the compounds of the invention may alsoexist as prodrugs. Accordingly, those skilled in the art will recognizethat reference to a compound herein, for example, reference to a“compound of the invention” or a “compound of formula I” includes acompound of formula I as well as pharmaceutically acceptable salts andprodrugs of that compound unless otherwise indicated. Further, the term“or a pharmaceutically acceptable salt and/or prodrug thereof” isintended to include all permutations of salts and prodrugs, such as apharmaceutically acceptable salt of a prodrug. Furthermore, solvates ofcompounds of formula I are included within the scope of this invention.

The compounds of the invention contain one or more chiral centers andtherefore, these compounds may be prepared and used in variousstereoisomeric forms. In some embodiments, in order to optimize thetherapeutic activity of the compounds of the invention, e.g., to treathypertension, it may be desirable that the carbon atoms have aparticular (R,R), (S,S), (S,R), or (R,S) configuration or are enrichedin a stereoisomeric form having such configuration. In otherembodiments, the compounds of the invention are present as racemicmixtures. Accordingly, the invention also relates to racemic mixtures,pure stereoisomers (e.g., enantiomers and diastereoisomers),stereoisomer-enriched mixtures, and the like unless otherwise indicated.When a chemical structure is depicted herein without anystereochemistry, it is understood that all possible stereoisomers areencompassed by such structure. Thus, for example, the term “compound offormula I” is intended to include all possible stereoisomers of thecompound. Similarly, when a particular stereoisomer is shown or namedherein, it will be understood by those skilled in the art that minoramounts of other stereoisomers may be present in the compositions of theinvention unless otherwise indicated, provided that the utility of thecomposition as a whole is not eliminated by the presence of such otherisomers. Individual stereoisomers may be obtained by numerous methodsthat are well known in the art, including chiral chromatography using asuitable chiral stationary phase or support, or by chemically convertingthem into diastereoisomers, separating the diastereoisomers byconventional means such as chromatography or recrystallization, thenregenerating the original stereoisomer.

Additionally, where applicable, all cis-trans or E/Z isomers (geometricisomers), tautomeric forms and topoisomeric forms of the compounds ofthe invention are included within the scope of the invention unlessotherwise specified. For example, if triazole is depicted as (R⁶⁰ beinghydrogen):

it is understood that the compound may also exist in a tautomeric formsuch as:

and that all such forms are covered by the invention.

The compounds of the invention, as well as those compounds used in theirsynthesis, may also include isotopically-labeled compounds, that is,where one or more atoms have been enriched with atoms having an atomicmass different from the atomic mass predominately found in nature.Examples of isotopes that may be incorporated into the compounds offormula I, for example, include, but are not limited to, ²H, ³H, ¹³C,¹⁴C, ¹⁵N, ¹⁸O, ¹⁷O, ³⁵S, ³⁶Cl, and ¹⁸F. Of particular interest arecompounds of formula I enriched in tritium or carbon-14 which can beused, for example, in tissue distribution studies; compounds of theinvention enriched in deuterium especially at a site of metabolismresulting, for example, in compounds having greater metabolic stability;and compounds of formula I enriched in a positron emitting isotope, suchas ¹¹C, ¹⁸F, ¹⁵O and ¹³N, which can be used, for example, in PositronEmission Topography (PET) studies.

The nomenclature used herein to name the compounds of the invention isillustrated in the Examples herein. This nomenclature has been derivedusing the commercially available AutoNom software (MDL, San Leandro,Calif.).

REPRESENTATIVE EMBODIMENTS

The following substituents and values are intended to providerepresentative examples of various aspects and embodiments of theinvention. These representative values are intended to further defineand illustrate such aspects and embodiments and are not intended toexclude other embodiments or to limit the scope of the invention. Inthis regard, the representation that a particular value or substituentis preferred is not intended in any way to exclude other values orsubstituents from the invention unless specifically indicated.

In one aspect, this invention relates to compounds of formula I:

R¹ is selected from the group consisting of H, —C₁₋₈alkyl,—CH(CH₃)OC(O)—O— cyclohexyl, —(CH₂)₂-morpholinyl, and—CH₂-5-methyl-[1,3]dioxol-2-one. In one embodiment, R¹ is H. In oneembodiment, R¹ is —C₁₋₈alkyl, for example —CH₂CH₃, —CH(CH₃)₂,—(CH₂)₃CH₃, and —(CH₂)₅CH₃. When R¹ is —C₁₋₈alkyl, the compound offormula I can be referred to as an alkyl ester, for example an ethylester. In one embodiment, R¹ is —CH(CH₃)OC(O)—O-cyclohexyl:

and the compound of formula I can be referred to as a cilexetil ester.In another embodiment, R¹ is —(CH₂)₂-morpholinyl:

and the compound of formula I can be referred to as a 2-morpholinoethylor mofetil ester. In yet another one embodiment, R¹ is—CH₂-5-methyl-[1,3]dioxol-2-one:

and the compound of formula I can be referred to as a medoxomil ester.In one particular embodiment, R¹ is H, —CH₂CH₃, —CH(CH₃)₂, —(CH₂)₃CH₃,or —(CH₂)₅CH₃.

R² is —CH₂—O—R²⁰, —C₀₋₁alkylene-NHC(O)—R²¹, —C₀₋₃alkylene-NR²²R²³,—CH₂—R²⁴, oxetane, 2-pyridine, 3-pyridine, thiophene, tetrahydropyran,or piperidine and having H or —C(O)CH₃ on the nitrogen, where thetetrahydropyran and piperidine rings are attached at the 4-position. TheR²⁰ moiety is —C₁₋₆alkyl, —CH₂NR²⁷CHR²⁸—, —C₂₋₃alkylene-OH, or—C₂₋₃alkylene-NR²⁹R³⁰. The R²¹ moiety is —C₁₋₆alkyl, —O—C₁₋₆alkyl,—C₀₋₆alkylene-NR²⁵R²⁵, —CH(NH₂)—R²⁶, —C₁₋₄alkylene-NHC(O)O—C₁₋₆alkyl,—OCH(CH₃)OC(O)CH(CH₃)₂, or pyrrolidine attached at a carbon atom. TheR²² moiety is H or —C₁₋₆alkyl. The R²³ moiety is H, —C₁₋₆alkyl,—C₁₋₆alkyl substituted with 1 to 6 fluoro atoms, —SO₂—C₁₋₆alkyl,—CH₂OC(O)—C₁₋₆alkyl, —C₂₋₄alkylene-OH, —C₂₋₄alkylene-O—CH₃, orcyclopropyl optionally substituted with one or two R³¹ groups. Inaddition, R²² and R²³ can be taken together to form —(CH₂)₂—O—(CH₂)₂—, a2-oxa-6-aza-spiro[3.3]heptane ring, or an azetidine ring optionallysubstituted with one or two R³¹ groups. The R²⁴ group is —CH₂OH, —CN,—C(O)NH₂, triazole or imidazole attached at a nitrogen atom, oroxadiazolone or tetrazole attached at the carbon atom. Each of the R²⁵groups are independently H or —CH₃. The R²⁶ group is —C₁₋₄alkylene-NH₂,—CH₂OH, or benzyl. The R²⁷ group is H, —C₁₋₆alkyl, —C₁₋₆alkylsubstituted with 1 to 6 fluoro atoms, —(CH₂)₂OH, or —(CH₂)₂OC₁₋₆alkyl.The R²⁸ group is H, —C₁₋₆alkyl, —C₁₋₂alkylene-OH, or—C₁₋₂alkylene-OC₁₋₆alkyl. The R²⁹ and R³⁰ groups are independently H,—C₁₋₆alkyl, —C₁₋₆alkyl substituted with 1 to 6 fluoro atoms, —(CH₂)₂OH,or —(CH₂)₂OC₁₋₆alkyl. In addition, R²⁹ and R³⁰ can be taken together toform —CH₂—CH₂—CH₂—. Each R³¹ group is independently halo (for example,fluoro or chloro), —C₁₋₆alkyl, —C₀₋₂alkylene-OH,—C₀₋₂alkylene-OC₁₋₆alkyl, —CN, or —CONH₂.

In one embodiment, R² is —CH₂—O—R²⁰ and R²⁰ is —C₁₋₆alkyl, for example,—CH₂—O—CH₃ or —CH₂—O—CH₂CH₃. In another embodiment, R² is —CH₂—O—R²⁰ andR²⁰ is —CH₂NR²⁷CHR²⁸—, where R²⁷ is H, —C₁₋₆alkyl, —C₁₋₆alkylsubstituted with 1 to 6 fluoro atoms (e.g., —CH₂CH₂CHF₂, —CH₂CH₂CH₂F,and —CH₂CH₂CF₃), —(CH₂)₂OH, or —(CH₂)₂OC₁₋₆alkyl, and R²⁸ is H,—C₁₋₆alkyl, —C₁₋₂alkylene-OH, or —C₁₋₂alkylene-OC₁₋₆alkyl (e.g.,—CH₂OCH₃, —CH₂OCH₂CH₃, and —(CH₂)₂OCH₃), for example,

In one particular embodiment, R²⁸ is H.

In still another embodiment, R² is —CH₂—O—R²⁰ and R²⁰ is—C₂₋₃alkylene-OH, for example, —CH₂—O—(CH₂)₂OH or —CH₂—O—(CH₂)₃₀H. Inyet another embodiment, R² is —CH₂—O—R²⁰ and R²⁰ is—C₂₋₃alkylene-NR²⁹R³⁰, where R²⁹ and R³⁰ are independently H,—C₁₋₆alkyl, —C₁₋₆alkyl substituted with 1 to 6 fluoro atoms, —(CH₂)₂OH,or —(CH₂)₂₀C₁₋₆alkyl, for example, —CH₂—O—(CH₂)₂NH₂, —CH₂—O—(CH₂)₃NH₂,—CH₂—O—(CH₂)₂NHCH₃, —CH₂—O—(CH₂)₃NHCH₃, —CH₂—O—(CH₂)₂N(CH₃)₂, or—CH₂—O—(CH₂)₂NH(CH₂CHF₂). In yet another embodiment, R² is —CH₂—O—R²⁰and R²⁰ is —C₂₋₃alkylene-NR²⁹R³⁰, where R²⁸ and R²⁹ are taken togetherto form are taken together to form —CH₂—CH₂—CH₂—, for example,

In one embodiment, R² is —C₀₋₁alkylene-NHC(O)—R²¹ and R²¹ is —C₁₋₆alkyl,for example, —NHC(O)CH₃, —NHC(O)CH₂CH₃, or —CH₂NHC(O)CH₃. In anotherembodiment, R² is —C₀₋₁alkylene-NHC(O)—R²¹ and R²¹ is —O—C₁₋₆alkyl, forexample, —NHC(O)OCH₃. In still another embodiment, R² is—C₀₋₁alkylene-NHC(O)—R²¹ and R²¹ is —C₀₋₆alkylene-NR²⁵R²⁵ (where eachR²⁵ group is independently H or —CH₃), for example, —NHC(O)CH₂NH₂,—CH₂NHC(O)CH₂NH₂, —NHC(O)(CH₂)₂NH₂, —NHC(O)(CH₂)₃NH₂,—CH₂NHC(O)(CH₂)₃NH₂, —NHC(O)(CH₂)₄NH₂, —NHC(O)(CH₂)₅NH₂,—NHC(O)CH(CH₃)NH₂, —CH₂NHC(O)C(CH₃)₂NH₂, —NHC(O)CH₂NH(CH₃),—NHC(O)CH₂N(CH₃)₂, —NHC(O)(CH₂)₃NH(CH₃), —NHC(O)(CH₂)₃N(CH₃)₂,—NHC(O)C(CH₃)₂NH₂, —NHC(O)CH(NH₂)—CH(CH₃)₂, or —CH₂NHC(O)C(CH₃)₂NH₂.

In yet another embodiment, R² is —C₀₋₁alkylene-NHC(O)—R²¹ and R²¹ is—CH(NH₂)—R²⁶ (where R²⁶ is —C₁₋₄alkylene-NH₂, —CH₂OH, or benzyl), forexample, —NHC(O)CH(NH₂)—(CH₂)₄NH₂, —NHC(O)CH(NH₂)—CH₂OH, or—NHC(O)CH(NH₂)-benzyl. In one embodiment, R² —C₀₋₁alkylene-NHC(O)—R²¹ isand R²¹ is —C₁₋₄alkylene-NHC(O)O—C₁₋₆alkyl, for example,—NHC(O)—CH₂—NHC(O)O—CH₃ and —NHC(O)—CH[CH(CH₃)₂]—NHC(O)O—CH₃.

In another embodiment, R² is —C₀₋₁alkylene-NHC(O)—R²¹ and R²¹ is—OCH(CH₃)OC(O)CH(CH₃)₂, for example, —NHC(O)OCH(CH₃)OC(O)CH(CH₃)₂ and—CH₂NHC(O)OCH(CH₃)OC(O)CH(CH₃)₂. In still another embodiment, R² is—C₀₋₁alkylene-NHC(O)—R²¹ and R²¹ is pyrrolidine, for example: (shownwithout stereochemistry and as the (S) isomer)

In another embodiment, R² is —C₀₋₃alkylene-NR²²R²³ (where R²² is H or—C₁₋₆alkyl, and R²³ is H, —C₁₋₆alkyl, —C₁₋₆alkyl substituted with 1 to 6fluoro atoms, —SO₂—C₁₋₆alkyl, —CH₂OC(O)—C₁₋₆alkyl, —C₂₋₄alkylene-OH,—C₂₋₄alkylene-O—CH₃, or cyclopropyl optionally substituted with one ortwo R³¹ groups, where each R³¹ is independently halo, —C₁₋₆alkyl,—C₀₋₂alkylene-OH, —C₀₋₂alkylene-OC₁₋₆alkyl, —CN, or —CONH₂. Examples ofthis embodiment include, for example, —NH₂, —CH₂NH₂, —CH(CH₃)NH₂,—C(CH₃)₂NH₂, —(CH₂)₂NH₂, —(CH₂)₃NH₂, —CH₂NH(CH₃), —CH₂N(CH₃)₂,—CH₂NH—CH₂CH₂F, —CH₂NH—CH₂CHF₂, —NH—SO₂CH₃, —NHCH₂OC(O)CH₃,—NHCH₂OC(O)CH(CH₃)₂, —CH₂NHCH₂OC(O)CH(CH₃)₂, —CH₂—NH—(CH₂)₂—OH,—CH₂—NH—(CH₂)₃—OH, —CH₂—N(CH₃)—(CH₂)₂—OH, —NH—(CH₂)₂—O—CH₃,—CH₂—NH—(CH₂)₂—O—CH₃, —CH₂—N(CH₃)—(CH₂)₂—O—CH₃, —NH—(CH₂)₃—O—CH₃,—CH₂—NH—(CH₂)₃—O—CH₃,

In another embodiment R² is —C₀₋₃alkylene-NR²²R²³ and R²² and R²³ takentogether to form —(CH₂)₂—O—(CH₂)₂—, a 2-oxa-6-aza-spiro[3.3]heptanering, or an azetidine ring optionally substituted with one or two R³¹groups, where each R³¹ group is independently halo, —C₁₋₆alkyl,—C₀₋₂alkylene-OH, —C₀₋₂alkylene-OC₁₋₆alkyl, —CN, or —CONH₂. Examples ofthis embodiment include:

In still another embodiment, R² is —CH₂—R²⁴ and R²⁴ is —CH₂OH, —CN,—C(O)NH₂, triazole or imidazole attached at a nitrogen atom, oroxadiazolone or tetrazole attached at the carbon atom, for example,—(CH₂)₂OH, —CH₂CN, —CH₂—C(O)NH₂,

In one embodiment, R² is oxetane, for example,

In another embodiment, R² is 2-pyridine or 3-pyridine:

In yet another embodiment, R² is thiophene, for example,

In another embodiment, R² is tetrahydropyran (attached at the4-position), for example,

In yet another embodiment, R² is piperidine (attached at the 4-position)having H or —C(O)CH₃ on the nitrogen, for example,

R³ is selected from the group consisting of H and halo, and in oneembodiment, R³ is H or Cl. R⁴ is selected from the group consisting of Hand halo, and in one embodiment, R⁴ is H or F. R⁵ is selected from thegroup consisting of H and halo, and in one embodiment, R⁵ is H, Br, orCl, and in another embodiment R⁵ is H or Cl. In other embodiments, R³ isH, R⁴ is F, and R⁵ is Cl; or R³ and R⁴ are H and R⁵ is Br or Cl; or R³,R⁴, and R⁵ are H; or R³ is Cl, R⁴ is F, and R⁵ is Cl; or R³ is H, R⁴ isF, and R⁵ is H.

R⁶ is a heterocycle selected from the group consisting of3H-oxazol-2-one, [1,2,4]oxadiazol-5-one, [1,2,3,5]oxatriazole,dihydro-[1,2,4]triazol-3-one, [1,2,4]triazolo[1,5-u]pyridine, triazole,pyrazole, imidazole, oxazole, isoxazole, isothiazole, pyridine,oxadiazole, and pyrimidine, where the heterocycle is attached at acarbon atom. In one embodiment, R⁶ is 3H-oxazol-2-one,4H-[1,2,4]oxadiazol-5-one, [1,2,3,5]oxatriazole, [1,2,3]triazole,[1,2,4]triazole, pyrazole, imidazole, oxazole, isoxazole, isothiazole,pyridine, oxadiazole, or pyrimidine. In another embodiment, R⁶ is3H-oxazol-2-one, 4H-[1,2,4]oxadiazol-5-one,[1,2,4]triazolo[1,5-a]pyridine, [1,2,3]triazole, [1,2,4]triazole,pyrazole, oxazole, isoxazole, isothiazole, pyridine, or pyrimidine.

Each nitrogen atom in the heterocycle is unsubstituted or substitutedwith an R⁶⁰ group selected from the group consisting of —OH, —(CH₂)₂OH,—C₀₋₂alkylene-O—C₁₋₆alkyl (e.g., —OCH₃ or —OCH₂CH₃), —C₁₋₆alkyl (e.g.,—CH₃), —CHF₂, —CF₃, and phenyl. In one embodiment, the nitrogen atoms inthe heterocycle are unsubstituted. In another embodiment, R⁶⁰ is —OH,—(CH₂)₂OH, —OCH₃, —OCH₂CH₃, —CH₃, —CHF₂, or —CF₃; in another embodimentR⁶⁰ is phenyl; and in yet another embodiment, one nitrogen atom in theheterocycle is substituted with an R⁶⁰ moiety.

Each carbon atom in the heterocycle is unsubstituted or substituted withan R⁶¹ group independently selected from the group consisting of halo,—OH, —C₁₋₆alkyl, —C₀₋₂alkylene-O—C₁₋₆alkyl, —C(O)CH₃, —C(O)NH(CH₃),—C(O)N(CH₃)₂, —C₃₋₆cycloalkyl (e.g., cyclopropyl, cyclobutyl,cyclopentyl, and cyclohexyl), —CF₃, —CH₂SO₂CH₃, —NH₂, —CH₂NH₂,—CH₂N(CH₃)₂, pyrazine, and phenyl substituted with methyl. In oneembodiment, the carbon atoms in the heterocycle are unsubstituted; andin another embodiment, one carbon atom in the heterocycle is substitutedwith an R⁶¹ group. In another embodiment, R⁶¹ is chloro, fluoro, —OH,—CH₃, —CH₂CH₃, —(CH₂)₂CH₃, —CH(CH₃)₂, —OCH₃, —OCH₂CH₃, —CH₂—OCH₃,—C(O)CH₃, —C(O)NH(CH₃), —C(O)N(CH₃)₂, cyclopropyl, —CF₃, —CH₂SO₂CH₃,—NH₂, —CH₂NH₂, —CH₂N(CH₃)₂, pyrazine, or phenyl substituted with methylor fluoro; and in one particular embodiment, R⁶¹ is chloro, fluoro, —OH,—CH₃, —CH₂CH₃, —(CH₂)₂CH₃, —CH(CH₃)₂, —OCH₃, —OCH₂CH₃, —C(O)CH₃,—C(O)NH(CH₃), —C(O)N(CH₃)₂, cyclopropyl, —CF₃, or phenyl substitutedwith methyl or fluoro.

In another embodiment, two carbon atoms in the heterocycle aresubstituted with R⁶¹ groups, which may be the same or different; and inone specific embodiment, the R⁶¹ moiety on a first carbon is selectedfrom the group consisting of fluoro, —OH, —CH₃,—C₀₋₂alkylene-O—C₁₋₆alkyl, —C(O)CH₃, —C₃₋₆cycloalkyl, —CF₃, —CH₂SO₂CH₃,—NH₂, and —CH₂N(CH₃)₂, and the R⁶¹ moiety on a second carbon is selectedfrom the group consisting of halo, —OH, —CH₃, —O—CH₂CH₃, —C(O)CH₃,cyclopropyl, —CF₃, —CH₂SO₂CH₃, —NH₂, —CH₂N(CH₃)₂, and phenyl substitutedwith methyl or halo. In one particular embodiment, a first carbon atomin the heterocycle is substituted with an R⁶¹ group selected from thegroup consisting of fluoro and —CH₃; and a second carbon atom in theheterocycle is substituted with an R⁶¹ group selected from the groupconsisting of —CH₃, —O—CH₂CH₃, cyclopropyl, and phenyl substituted withmethyl.

In one embodiment, R⁶ is 3H-oxazol-2-one, for example:

In one embodiment, R⁶ is [1,2,4]oxadiazol-5-one, for example4H-[1,2,4]oxadiazol-5-one or 2H-[1,2,4]oxadiazol-5-one:

In one embodiment, R⁶ is [1,2,3,5]oxatriazole, for example:

In one embodiment, R⁶ is dihydro-[1,2,4]triazol-3-one, for example2,4-dihydro-[1,2,4]triazol-3-one or 4,5-dihydro-[1,2,4]triazol-3-one:

In one particular embodiment, R⁶ is a 2,4-dihydro-[1,2,4]triazol-3-onering such as:

specific examples of which include:

In one embodiment, R⁶ is [1,2,4]triazolo[1,5-c]pyridine, for example:

In one particular embodiment, R⁶ is a [1,2,4]triazolo[1,5-a]pyridinering such as:

specific examples of which include:

In one embodiment, R⁶ is [1,2,3]triazole or [1,2,4]triazole, forexample:

specific examples of which include:

In one particular embodiment, R⁶ is a triazole ring such as:

specific examples of which include:

In one embodiment, R⁶ is a pyrazole ring, for example:

In one particular embodiment, R⁶ is a pyrazole ring such as:

specific examples of which include:

In one embodiment, R⁶ is an imidazole ring, for example:

In one particular embodiment, R⁶ is an imidazole ring such as:

specific examples of which include:

In one embodiment, R⁶ is an oxazole ring, for example:

In one particular embodiment, R⁶ is an oxazole ring such as:

specific examples of which include:

In one embodiment, R⁶ is an isoxazole ring, for example:

In one particular embodiment, R⁶ is an isoxazole ring such as:

specific examples of which include:

In one embodiment, R⁶ is an isothiazole ring, for example:

In one particular embodiment, R⁶ is an isothiazole ring such as:

specific examples of which include:

In one embodiment, R⁶ is a pyridine ring, for example:

In one particular embodiment, R⁶ is a pyridine ring such as:

specific examples of which include:

In one embodiment, R⁶ is oxadiazole, for example [1,2,4]oxadiazole or[1,3,4]oxadiazole:

In one embodiment, R⁶ is a pyrimidine ring, for example:

In addition, particular compounds of formula I that are of interestinclude those set forth in the Examples below, as well aspharmaceutically acceptable salts thereof.

General Synthetic Procedures

Compounds of the invention can be prepared from readily availablestarting materials using the following general methods, the proceduresset forth in the Examples, or by using other methods, reagents, andstarting materials that are known to those of ordinary skill in the art.Although the following procedures may illustrate a particular embodimentof the invention, it is understood that other embodiments of theinvention can be similarly prepared using the same or similar methods orby using other methods, reagents and starting materials known to thoseof ordinary skill in the art. It will also be appreciated that wheretypical or preferred process conditions (for example, reactiontemperatures, times, mole ratios of reactants, solvents, pressures,etc.) are given, other process conditions can also be used unlessotherwise stated. In some instances, reactions were conducted at roomtemperature and no actual temperature measurement was taken. It isunderstood that room temperature can be taken to mean a temperaturewithin the range commonly associated with the ambient temperature in alaboratory environment, and will typically be in the range of about 18°C. to about 30° C. In other instances, reactions were conducted at roomtemperature and the temperature was actually measured and recorded.While optimum reaction conditions will typically vary depending onvarious reaction parameters such as the particular reactants, solventsand quantities used, those of ordinary skill in the art can readilydetermine suitable reaction conditions using routine optimizationprocedures.

Additionally, as will be apparent to those skilled in the art,conventional protecting groups may be necessary or desired to preventcertain functional groups from undergoing undesired reactions. Thechoice of a suitable protecting group for a particular functional groupas well as suitable conditions and reagents for protection anddeprotection of such functional groups are well-known in the art.Protecting groups other than those illustrated in the proceduresdescribed herein may be used, if desired. For example, numerousprotecting groups, and their introduction and removal, are described inT. W. Greene and G. M. Wuts, Protecting Groups in Organic Synthesis,Fourth Edition, Wiley, New York, 2006, and references cited therein.

Carboxy-protecting groups are suitable for preventing undesiredreactions at a carboxy group, and examples include, but are not limitedto, methyl, ethyl, t-butyl, benzyl (Bn), p-methoxybenzyl (PMB),9-fluorenylmethyl (Fm), trimethylsilyl (TMS), t-butyldimethylsilyl(TBDMS), diphenylmethyl (benzhydryl, DPM) and the like. Amino-protectinggroups are suitable for preventing undesired reactions at an aminogroup, and examples include, but are not limited to, t-butoxycarbonyl(BOC), trityl (Tr), benzyloxycarbonyl (Cbz), 9-fluorenylmethoxycarbonyl(Fmoc), formyl, trimethylsilyl (TMS), t-butyldimethylsilyl (TBDMS), andthe like. Hydroxyl-protecting groups are suitable for preventingundesired reactions at a hydroxyl group, and examples include, but arenot limited to C₁₋₆alkyls, silyl groups including triC₁₋₆alkylsilylgroups, such as trimethylsilyl (TMS), triethylsilyl (TES), andtert-butyldimethylsilyl (TBDMS); esters (acyl groups) includingC₁₋₆alkanoyl groups, such as formyl, acetyl, and pivaloyl, and aromaticacyl groups such as benzoyl; arylmethyl groups such as benzyl (Bn),p-methoxybenzyl (PMB), 9-fluorenylmethyl (Fm), and diphenylmethyl(benzhydryl, DPM); and the like.

Standard deprotection techniques and reagents are used to remove theprotecting groups, and may vary depending upon which group is used. Forexample, a BOC amino-protecting group can be removed using an acidicreagent such as TFA in DCM or HCl in 1,4-dioxane, while a Cbzamino-protecting group can be removed by employing catalytichydrogenation conditions such as H₂ (1 atm) and 10% Pd/C in an alcoholicsolvent (“H₂/Pd/C”).

Suitable bases for use in these schemes include, by way of illustrationand not limitation, potassium carbonate, calcium carbonate, sodiumcarbonate, triethylamine (Et₃N), pyridine,1,8-diazabicyclo-[5.4.0]undec-7-ene (DBU), N,N-diisopropylethylamine(DIPEA), 4-methylmorpholine, sodium hydroxide, potassium hydroxide,potassium t-butoxide, and metal hydrides.

Suitable inert diluents or solvents for use in these schemes include, byway of illustration and not limitation, tetrahydrofuran (THF),acetonitrile (MeCN), N,N-dimethylformamide (DMF), N,N-dimethylacetamide(DMA), dimethyl sulfoxide (DMSO), toluene, dichloromethane (DCM),chloroform (CHCl₃), carbon tetrachloride (CCl₄), 1,4-dioxane, methanol,ethanol, water, diethyl ether, acetone, and the like.

Suitable carboxylic acid/amine coupling reagents includebenzotriazol-1-yloxytris(dimethylamino)phosphonium hexafluorophosphate(BOP), benzotriazol-1-yloxytripyrrolidinophosphonium hexafluorophosphate(PyBOP), N,N,N′,N′-tetramethyl-O-(7-azabenzotriazol-1-yl)uroniumhexafluorophosphate (HATU), 1,3-dicyclohexylcarbodiimide (DCC),N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide (EDC),carbonyldiimidazole (CDI), 1-hydroxybenzotriazole (HOBt), and the like.Coupling reactions are conducted in an inert diluent in the presence ofa base such as DIPEA, and are performed under conventional amidebond-forming conditions.

All reactions are typically conducted at a temperature within the rangeof about −78 C to 100° C., for example at room temperature. Reactionsmay be monitored by use of thin layer chromatography (TLC), highperformance liquid chromatography (HPLC), and/or LCMS until completion.Reactions may be complete in minutes, or may take hours, typically from1-2 hours and up to 48 hours. Upon completion, the resulting mixture orreaction product may be further treated in order to obtain the desiredproduct. For example, the resulting mixture or reaction product may besubjected to one or more of the following procedures: concentrating orpartitioning (for example, between EtOAc and water or between 5% THF inEtOAc and 1M phosphoric acid); extraction (for example, with EtOAc,CHCl₃, DCM, chloroform); washing (for example, with saturated aqueousNaCl, saturated aqueous NaHCO₃, Na₂CO₃ (5%), CHCl₃ or 1M NaOH); drying(for example, over MgSO₄, over Na₂SO₄, or in vacuo); filtering;crystallizing (for example, from EtOAc and hexanes); being concentrated(for example, in vacuo); and/or purification (e.g., silica gelchromatography, flash chromatography, preparative HPLC, reversephase-HPLC, or crystallization).

By way of illustration, compounds of formula I, as well as their salts,can be prepared as shown in Schemes I and II.

Scheme I is a is a coupling reaction between a compound of formula 1(R¹-R⁵ are as defined for formula I and P¹ is H or a suitableamino-protecting group) and a compound of formula 2 (R⁶ is as definedfor formula I). When P¹ is an amino protecting group, the processfurther comprises deprotecting the compound, before or in situ with thecoupling step. Exemplary coupling reagents include HATU, and HOBt withEDC. Generally, this reaction is conducted in the presence of a basesuch as DIPEA or 4-methylmorpholine, and an inert diluent or solventssuch as DMF or DMA. Preparation of various amine starting materials(Compound 1) are illustrated in the Examples. The carboxylic acidstarting materials (Compound 2) are generally commercially available orcan be prepared using procedures that are known in the art.

Scheme II is a transesterification reaction. Generally, this reactioninvolves reacting the ester compound of formula 3 (R²-R⁶ are as definedfor formula I) with the desired alcohol compound of formula 4 (R¹ is asdefined for formula I) and a suitable acid catalyst, for examplehydrochloric acid. Preparation of the compound of formula 3 from theacid (the compound of formula I) is known in the art or is describedherein. The HO—R¹ alcohols are either commercially available or can beprepared by techniques that are known in the art or described herein.Exemplary HO—R¹ groups include:

Certain intermediates described herein are believed to be novel andaccordingly, such compounds are provided as further aspects of theinvention including, for example, the compounds of formula 1 or a saltthereof:

where R¹-R⁵ are as defined for formula I and P¹ is H or a suitableamino-protecting group selected from the group consisting oft-butoxycarbonyl, trityl, benzyloxycarbonyl, 9-fluorenylmethoxycarbonyl,formyl, trimethylsilyl, and t-butyldimethylsilyl; or a salt thereof.

Further details regarding specific reaction conditions and otherprocedures for preparing representative compounds of the invention orintermediates thereof are described in the Examples set forth below.

Utility

Compounds of the invention possess neprilysin (NEP) inhibition activity,that is, the compounds are able to inhibit enzyme-catalytic activity. Inanother embodiment, the compounds do not exhibit significant inhibitoryactivity of the angiotensin-converting enzyme. One measure of theability of a compound to inhibit NEP activity is the inhibition constant(pK_(i)). The pK_(i) value is the negative logarithm to base 10 of thedissociation constant (K_(i)), which is typically reported in molarunits. Compounds of the invention of particular interest are thosehaving a pK_(i) at NEP greater than or equal to 7.0, and even moreparticularly those having a pK_(i) greater than or equal to 8.0; and instill another embodiment, compounds of interest have a pK_(i) in therange of greater than or equal to 9.0. Such values can be determined bytechniques that are well known in the art, as well as in the assaysdescribed herein.

Another measure of the ability of a compound to inhibit NEP activity isthe apparent inhibition constant (IC₅₀), which is the molarconcentration of compound that results in half-maximal inhibition ofsubstrate conversion by the NEP enzyme. The pIC₅₀ value is the negativelogarithm to base 10 of the IC₅₀. Compounds of the invention that are ofparticular interest, include those that exhibit a pIC₅₀ for NEP greaterthan or equal to about 7.0. In another embodiment, compounds of interesthave a pIC₅₀ for NEP within the range of about 7.0-10.0.

It is noted that in some cases, compounds of the invention may possessweak NEP inhibition activity. In such cases, those of skill in the artwill recognize that these compounds still have utility as researchtools.

Exemplary assays to determine properties of compounds of the invention,such as the NEP inhibiting activity, are described in the Examples andinclude by way of illustration and not limitation, assays that measureNEP inhibition (described in Assay 1). Useful secondary assays includeassays to measure ACE inhibition (also described in Assay 1) andaminopeptidase P (APP) inhibition (described in Sulpizio et al. (2005)JPET 315:1306-1313). A pharmacodynamic assay to assess the in vivoinhibitory potencies for ACE and NEP in anesthetized rats is describedin Assay 2 (see also Seymour et al. (1985) Hypertension 7(SupplI):I-35-I-42 and Wigle et al. (1992) Can. J Physiol. Pharmacol.70:1525-1528), where ACE inhibition is measured as the percentinhibition of the angiotensin I pressor response and NEP inhibition ismeasured as increased urinary cyclic guanosine 3′, 5′-monophosphate(cGMP) output.

There are many in vivo assays that can be used to ascertain furtherutilities of the compounds of the invention. The conscious spontaneouslyhypertensive rat (SHR) model is a renin dependent hypertension model,and is described in Assay 3. See also Intengan et al. (1999) Circulation100(22):2267-2275 and Badyal et al. (2003) Indian Journal ofPharmacology 35:349-362. The conscious desoxycorticosterone acetate-salt(DOCA-salt) rat model is a volume dependent hypertension model that isuseful for measuring NEP activity, and is described in Assay 4. See alsoTrapani et al. (1989) J. Cardiovasc. Pharmacol. 14:419-424, Intengan etal. (1999) Hypertension 34(4):907-913, and Badyal et al. (2003) supra).The DOCA-salt model is particularly useful for evaluating the ability ofa test compound to reduce blood pressure as well as to measure a testcompound's ability to prevent or delay a rise in blood pressure. TheDahl salt-sensitive (DSS) hypertensive rat model is a model ofhypertension that is sensitive to dietary salt (NaCl), and is describedin Assay 5. See also Rapp (1982) Hypertension 4:753-763. The ratmonocrotaline model of pulmonary arterial hypertension described, forexample, in Kato et al. (2008) J. Cardiovasc. Pharmacol. 51(1):18-23, isa reliable predictor of clinical efficacy for the treatment of pulmonaryarterial hypertension. Heart failure animal models include the DSS ratmodel for heart failure and the aorto-caval fistula model (AV shunt),the latter of which is described, for example, in Norling et al. (1996)J. Amer. Soc. Nephrol. 7:1038-1044. Other animal models, such as the hotplate, tail-flick and formalin tests, can be used to measure theanalgesic properties of compounds of the invention, as well as thespinal nerve ligation (SNL) model of neuropathic pain. See, for example,Malmberg et al. (1999) Current Protocols in Neuroscience 8.9.1-8.9.15.Other properties and utilities of the compounds can be demonstratedusing various in vitro and in vivo assays well known to those skilled inthe art.

Depending upon the intended route of administration, oralbioavailability may be an important characteristic, as well as potencyas a neprilysin inhibitor. One means of measuring oral bioavailabilityis by the rat PO cassette assay, where the % F is a measure of theamount of the oral drug dose that actually gets into the blood stream;an exemplary assay is described in Assay 6. Compounds tested in thisassay and having a % F<10% are likely to be poorly absorbed. Similarly,compounds tested in this assay and having a % F>10% are likely to bebetter absorbed. Therefore, compounds of the invention having a % F>10%are of particular interest as orally administered drugs.

Compounds of the invention are expected to inhibit the NEP enzyme in anyof the assays listed above, or assays of a similar nature. Thus, theaforementioned assays are useful in determining the therapeutic utilityof compounds of the invention, for example, their utility asantihypertensive agents or antidiarrheal agents. Other properties andutilities of compounds of the invention can be demonstrated using otherin vitro and in vivo assays well-known to those skilled in the art.Compounds of formula I may be active drugs as well as prodrugs. Thus,when discussing the activity of compounds of the invention, it isunderstood that any such prodrugs may not exhibit the expected activityin an assay, but are expected to exhibit the desired activity oncemetabolized.

Compounds of the invention are expected to be useful for the treatmentand/or prevention of medical conditions responsive to NEP inhibition.Thus it is expected that patients suffering from a disease or disorderthat is treated by inhibiting the NEP enzyme or by increasing the levelsof its peptide substrates, can be treated by administering atherapeutically effective amount of a compound of the invention. Forexample, by inhibiting NEP, the compounds are expected to potentiate thebiological effects of endogenous peptides that are metabolized by NEP,such as the natriuretic peptides, bombesin, bradykinins, calcitonin,endothelins, enkephalins, neurotensin, substance P and vasoactiveintestinal peptide. Thus, these compounds are expected to have otherphysiological actions, for example, on the renal, central nervous,reproductive and gastrointestinal systems.

Cardiovascular Diseases

By potentiating the effects of vasoactive peptides like the natriureticpeptides and bradykinin, compounds of the invention are expected to findutility in treating and/or preventing medical conditions such ascardiovascular diseases. See, for example, Roques et al. (1993)Pharmacol. Rev. 45:87-146 and Dempsey et al. (2009) Amer. J. ofPathology 174(3):782-796. Cardiovascular diseases of particular interestinclude hypertension and heart failure. Hypertension includes, by way ofillustration and not limitation: primary hypertension, which is alsoreferred to as essential hypertension or idiopathic hypertension;secondary hypertension; hypertension with accompanying renal disease;severe hypertension with or without accompanying renal disease;pulmonary hypertension, including pulmonary arterial hypertension; andresistant hypertension. Heart failure includes, by way of illustrationand not limitation: congestive heart failure; acute heart failure;chronic heart failure, for example with reduced left ventricularejection fraction (also referred to as systolic heart failure) or withpreserved left ventricular ejection fraction (also referred to asdiastolic heart failure); and acute and chronic decompensated heartfailure. Thus, one embodiment of the invention relates to a method fortreating hypertension, particularly primary hypertension or pulmonaryarterial hypertension, comprising administering to a patient atherapeutically effective amount of a compound of the invention.

For treatment of primary hypertension, the therapeutically effectiveamount is typically the amount that is sufficient to lower the patient'sblood pressure. This would include both mild-to-moderate hypertensionand severe hypertension. When used to treat hypertension, the compoundmay be administered in combination with other therapeutic agents such asaldosterone antagonists, aldosterone synthase inhibitors,angiotensin-converting enzyme inhibitors and dual-actingangiotensin-converting enzyme/neprilysin inhibitors,angiotensin-converting enzyme 2 (ACE2) activators and stimulators,angiotensin-II vaccines, anti-diabetic agents, anti-lipid agents,anti-thrombotic agents, AT₁ receptor antagonists and dual-acting AT₁receptor antagonist/neprilysin inhibitors, β₁-adrenergic receptorantagonists, dual-acting β-adrenergic receptor antagonist/α₁-receptorantagonists, calcium channel blockers, diuretics, endothelin receptorantagonists, endothelin converting enzyme inhibitors, neprilysininhibitors, natriuretic peptides and their analogs, natriuretic peptideclearance receptor antagonists, nitric oxide donors, non-steroidalanti-inflammatory agents, phosphodiesterase inhibitors (specificallyPDE-V inhibitors), prostaglandin receptor agonists, renin inhibitors,soluble guanylate cyclase stimulators and activators, and combinationsthereof. In one particular embodiment of the invention, a compound ofthe invention is combined with an AT₁ receptor antagonist, a calciumchannel blocker, a diuretic, or a combination thereof, and used to treatprimary hypertension. In another particular embodiment of the invention,a compound of the invention is combined with an AT₁ receptor antagonist,and used to treat hypertension with accompanying renal disease. Whenused to treat resistant hypertension, the compound may be administeredin combination with other therapeutic agents such as aldosteronesynthase inhibitors.

For treatment of pulmonary arterial hypertension, the therapeuticallyeffective amount is typically the amount that is sufficient to lower thepulmonary vascular resistance. Other goals of therapy are to improve apatient's exercise capacity. For example, in a clinical setting, thetherapeutically effective amount can be the amount that improves apatient's ability to walk comfortably for a period of 6 minutes(covering a distance of approximately 20-40 meters). When used to treatpulmonary arterial hypertension the compound may be administered incombination with other therapeutic agents such as α-adrenergic receptorantagonists, β₁-adrenergic receptor antagonists, β₂-adrenergic receptoragonists, angiotensin-converting enzyme inhibitors, anticoagulants,calcium channel blockers, diuretics, endothelin receptor antagonists,PDE-V inhibitors, prostaglandin analogs, selective serotonin reuptakeinhibitors, and combinations thereof. In one particular embodiment ofthe invention, a compound of the invention is combined with a PDE-Vinhibitor or a selective serotonin reuptake inhibitor and used to treatpulmonary arterial hypertension.

Another embodiment of the invention relates to a method for treatingheart failure, in particular congestive heart failure (including bothsystolic and diastolic congestive heart failure), comprisingadministering to a patient a therapeutically effective amount of acompound of the invention. Typically, the therapeutically effectiveamount is the amount that is sufficient to lower blood pressure and/orimprove renal functions. In a clinical setting, the therapeuticallyeffective amount can be the amount that is sufficient to improve cardiachemodynamics, like for instance reduction in wedge pressure, rightatrial pressure, filling pressure, and vascular resistance. In oneembodiment, the compound is administered as an intravenous dosage form.When used to treat heart failure, the compound may be administered incombination with other therapeutic agents such as adenosine receptorantagonists, advanced glycation end product breakers, aldosteroneantagonists, AT₁ receptor antagonists, β₁-adrenergic receptorantagonists, dual-acting β-adrenergic receptor antagonist/α₁-receptorantagonists, chymase inhibitors, digoxin, diuretics, endothelinconverting enzyme (ECE) inhibitors, endothelin receptor antagonists,natriuretic peptides and their analogs, natriuretic peptide clearancereceptor antagonists, nitric oxide donors, prostaglandin analogs, PDE-Vinhibitors, soluble guanylate cyclase activators and stimulators, andvasopressin receptor antagonists. In one particular embodiment of theinvention, a compound of the invention is combined with an aldosteroneantagonist, a β₁-adrenergic receptor antagonist, an AT₁ receptorantagonist, or a diuretic, and used to treat congestive heart failure.

Diarrhea

As NEP inhibitors, compounds of the invention are expected to inhibitthe degradation of endogenous enkephalins and thus such compounds mayalso find utility for the treatment of diarrhea, including infectiousand secretory/watery diarrhea. See, for example, Baumer et al. (1992)Gut 33:753-758; Farthing (2006) Digestive Diseases 24:47-58; andMarçais-Collado (1987) Eur. J Pharmacol. 144(2):125-132. When used totreat diarrhea, compounds of the invention may be combined with one ormore additional antidiarrheal agents.

Renal Diseases

By potentiating the effects of vasoactive peptides like the natriureticpeptides and bradykinin, compounds of the invention are expected toenhance renal function (see Chen et al. (1999) Circulation100:2443-2448; Lipkin et al. (1997) Kidney Int. 52:792-801; and Dussauleet al. (1993) Clin. Sci. 84:31-39) and find utility in treating and/orpreventing renal diseases. Renal diseases of particular interest includediabetic nephropathy, chronic kidney disease, proteinuria, andparticularly acute kidney injury (caused, for example, by cardiovascularsurgery, chemotherapy, or the use of contrast dyes in medical imaging)or acute renal failure (see Sharkovska et al. (2011) Clin. Lab.57:507-515 and Newaz et al. (2010) Renal Failure 32:384-390). When usedto treat renal disease, the compound may be administered in combinationwith other therapeutic agents such as angiotensin-converting enzymeinhibitors, AT₁ receptor antagonists, and diuretics.

Preventative Therapy

By potentiating the effects of the natriuretic peptides, compounds ofthe invention are also expected to be useful in preventative therapy,due to the antihypertrophic and antifibrotic effects of the natriureticpeptides (see Potter et al. (2009) Handbook of Experimental Pharmacology191:341-366), for example in preventing the progression of cardiacinsufficiency after myocardial infarction, preventing arterialrestenosis after angioplasty, preventing thickening of blood vesselwalls after vascular operations, preventing atherosclerosis, andpreventing diabetic angiopathy.

Glaucoma

By potentiating the effects of the natriuretic peptides, compounds ofthe invention are expected to be useful to treat glaucoma. See, forexample, Diestelhorst et al. (1989) International Ophthalmology12:99-101. When used to treat glaucoma, compounds of the invention maybe combined with one or more additional antiglaucoma agents.

Pain Relief

As NEP inhibitors, compounds of the invention are expected to inhibitthe degradation of endogenous enkephalins and thus such compounds mayalso find utility as analgesics. See, for example, Roques et al. (1980)Nature 288:286-288 and Thanawala et al. (2008) Current Drug Targets9:887-894. When used to treat pain, the compounds of the invention maybe combined with one or more additional antinociceptive drugs such asaminopeptidase N or dipeptidyl peptidase III inhibitors, non-steroidalanti-inflammatory agents, monoamine reuptake inhibitors, musclerelaxants, NMDA receptor antagonists, opioid receptor agonists,5-HT_(1D) serotonin receptor agonists, and tricyclic antidepressants.

Other Utilities

Due to their NEP inhibition properties, compounds of the invention arealso expected to be useful as antitussive agents, as well as findutility in the treatment of portal hypertension associated with livercirrhosis (see Sansoe et al. (2005) J. Hepatol. 43:791-798), cancer (seeVesely (2005) J. Investigative Med. 53:360-365), depression (see Nobleet al. (2007) Exp. Opin. Ther. Targets 11:145-159), menstrual disorders,preterm labor, pre-eclampsia, endometriosis, reproductive disorders (forexample, male and female infertility, polycystic ovarian syndrome,implantation failure), and male and female sexual dysfunction, includingmale erectile dysfunction and female sexual arousal disorder. Morespecifically, the compounds of the invention are expected to be usefulin treating female sexual dysfunction (see Pryde et al. (2006) J. Med.Chem. 49:4409-4424), which is often defined as a female patient'sdifficulty or inability to find satisfaction in sexual expression. Thiscovers a variety of diverse female sexual disorders including, by way ofillustration and not limitation, hypoactive sexual desire disorder,sexual arousal disorder, orgasmic disorder and sexual pain disorder.When used to treat such disorders, especially female sexual dysfunction,compounds of the invention may be combined with one or more of thefollowing secondary agents: PDE-V inhibitors, dopamine agonists,estrogen receptor agonists and/or antagonists, androgens, and estrogens.Due to their NEP inhibition properties, compounds of the invention arealso expected to have anti-inflammatory properties, and are expected tohave utility as such, particularly when used in combination withstatins.

Recent studies suggest that NEP plays a role in regulating nervefunction in insulin-deficient diabetes and diet induced obesity. Coppeyet al. (2011) Neuropharmacology 60:259-266. Therefore, due to their NEPinhibition properties, compounds of the invention are also expected tobe useful in providing protection from nerve impairment caused bydiabetes or diet induced obesity.

The amount of the compound of the invention administered per dose or thetotal amount administered per day may be predetermined or it may bedetermined on an individual patient basis by taking into considerationnumerous factors, including the nature and severity of the patient'scondition, the condition being treated, the age, weight, and generalhealth of the patient, the tolerance of the patient to the active agent,the route of administration, pharmacological considerations such as theactivity, efficacy, pharmacokinetics and toxicology profiles of thecompound and any secondary agents being administered, and the like.Treatment of a patient suffering from a disease or medical condition(such as hypertension) can begin with a predetermined dosage or a dosagedetermined by the treating physician, and will continue for a period oftime necessary to prevent, ameliorate, suppress, or alleviate thesymptoms of the disease or medical condition. Patients undergoing suchtreatment will typically be monitored on a routine basis to determinethe effectiveness of therapy. For example, in treating hypertension,blood pressure measurements may be used to determine the effectivenessof treatment. Similar indicators for other diseases and conditionsdescribed herein, are well known and are readily available to thetreating physician. Continuous monitoring by the physician will insurethat the optimal amount of the compound of the invention will beadministered at any given time, as well as facilitating thedetermination of the duration of treatment. This is of particular valuewhen secondary agents are also being administered, as their selection,dosage, and duration of therapy may also require adjustment. In thisway, the treatment regimen and dosing schedule can be adjusted over thecourse of therapy so that the lowest amount of active agent thatexhibits the desired effectiveness is administered and, further, thatadministration is continued only so long as is necessary to successfullytreat the disease or medical condition.

Research Tools

Since compounds of the invention possess NEP enzyme inhibition activity,such compounds are also useful as research tools for investigating orstudying biological systems or samples having a NEP enzyme, for exampleto study diseases where the NEP enzyme or its peptide substrates plays arole. Any suitable biological system or sample having a NEP enzyme maybe employed in such studies which may be conducted either in vitro or invivo. Representative biological systems or samples suitable for suchstudies include, but are not limited to, cells, cellular extracts,plasma membranes, tissue samples, isolated organs, mammals (such asmice, rats, guinea pigs, rabbits, dogs, pigs, humans, and so forth), andthe like, with mammals being of particular interest. In one particularembodiment of the invention, NEP enzyme activity in a mammal isinhibited by administering a NEP-inhibiting amount of a compound of theinvention. Compounds of the invention can also be used as research toolsby conducting biological assays using such compounds.

When used as a research tool, a biological system or sample comprising aNEP enzyme is typically contacted with a NEP enzyme-inhibiting amount ofa compound of the invention. After the biological system or sample isexposed to the compound, the effects of inhibiting the NEP enzyme aredetermined using conventional procedures and equipment, such as bymeasuring receptor binding in a binding assay or measuringligand-mediated changes in a functional assay. Exposure encompassescontacting cells or tissue with the compound, administering the compoundto a mammal, for example by i.p., p.o, i.v., s.c., or inhaledadministration, and so forth. This determining step can involvemeasuring a response (a quantitative analysis) or can involve making anobservation (a qualitative analysis). Measuring a response involves, forexample, determining the effects of the compound on the biologicalsystem or sample using conventional procedures and equipment, such asenzyme activity assays and measuring enzyme substrate or productmediated changes in functional assays. The assay results can be used todetermine the activity level as well as the amount of compound necessaryto achieve the desired result, that is, a NEP enzyme-inhibiting amount.Typically, the determining step will involve determining the effects ofinhibiting the NEP enzyme.

Additionally, compounds of the invention can be used as research toolsfor evaluating other chemical compounds, and thus are also useful inscreening assays to discover, for example, new compounds havingNEP-inhibiting activity. In this manner, a compound of the invention isused as a standard in an assay to allow comparison of the resultsobtained with a test compound and with compounds of the invention toidentify those test compounds that have about equal or superioractivity, if any. For example, pK_(i) data for a test compound or agroup of test compounds is compared to the pK_(i) data for a compound ofthe invention to identify those test compounds that have the desiredproperties, for example, test compounds having a pK_(i) value aboutequal or superior to a compound of the invention, if any. This aspect ofthe invention includes, as separate embodiments, both the generation ofcomparison data (using the appropriate assays) and the analysis of testdata to identify test compounds of interest. Thus, a test compound canbe evaluated in a biological assay, by a method comprising the steps of:(a) conducting a biological assay with a test compound to provide afirst assay value; (b) conducting the biological assay with a compoundof the invention to provide a second assay value; wherein step (a) isconducted either before, after or concurrently with step (b); and (c)comparing the first assay value from step (a) with the second assayvalue from step (b). Exemplary biological assays include a NEP enzymeinhibition assay.

Still another aspect of the invention relates to a method of studying abiological system or sample comprising a NEP enzyme, the methodcomprising: (a) contacting the biological system or sample with acompound of the invention; and (b) determining the effects caused by thecompound on the biological system or sample.

Pharmaceutical Compositions and Formulations

Compounds of the invention are typically administered to a patient inthe form of a pharmaceutical composition or formulation. Suchpharmaceutical compositions may be administered to the patient by anyacceptable route of administration including, but not limited to, oral,rectal, vaginal, nasal, inhaled, topical (including transdermal),ocular, and parenteral modes of administration. Further, the compoundsof the invention may be administered, for example orally, in multipledoses per day (for example, two, three, or four times daily), in asingle daily dose or a single weekly dose. It will be understood thatany form of the compounds of the invention, (that is, free base, freeacid, pharmaceutically acceptable salt, solvate, etc.) that is suitablefor the particular mode of administration can be used in thepharmaceutical compositions discussed herein.

Accordingly, in one embodiment, the invention relates to apharmaceutical composition comprising a pharmaceutically acceptablecarrier and a compound of the invention. The compositions may containother therapeutic and/or formulating agents if desired. When discussingcompositions, the “compound of the invention” may also be referred toherein as the “active agent,” to distinguish it from other components ofthe formulation, such as the carrier. Thus, it is understood that theterm “active agent” includes compounds of formula I as well aspharmaceutically acceptable salts, solvates and prodrugs of thatcompound.

The pharmaceutical compositions of the invention typically contain atherapeutically effective amount of a compound of the invention. Thoseskilled in the art will recognize, however, that a pharmaceuticalcomposition may contain more than a therapeutically effective amount,such as in bulk compositions, or less than a therapeutically effectiveamount, that is, individual unit doses designed for multipleadministration to achieve a therapeutically effective amount. Typically,the composition will contain from about 0.01-95 wt % of active agent,including, from about 0.01-30 wt %, such as from about 0.01-10 wt %,with the actual amount depending upon the formulation itself, the routeof administration, the frequency of dosing, and so forth. In oneembodiment, a composition suitable for an oral dosage form, for example,may contain about 5-70 wt %, or from about 10-60 wt % of active agent.

Any conventional carrier or excipient may be used in the pharmaceuticalcompositions of the invention. The choice of a particular carrier orexcipient, or combinations of carriers or excipients, will depend on themode of administration being used to treat a particular patient or typeof medical condition or disease state. In this regard, the preparationof a suitable composition for a particular mode of administration iswell within the scope of those skilled in the pharmaceutical arts.Additionally, carriers or excipients used in such compositions arecommercially available. By way of further illustration, conventionalformulation techniques are described in Remington: The Science andPractice of Pharmacy, 20^(th) Edition, Lippincott Williams & White,Baltimore, Md. (2000); and H. C. Ansel et al., Pharmaceutical DosageForms and Drug Delivery Systems, 7^(th) Edition, Lippincott Williams &White, Baltimore, Md. (1999).

Representative examples of materials which can serve as pharmaceuticallyacceptable carriers include, but are not limited to, the following:sugars, such as lactose, glucose and sucrose; starches, such as cornstarch and potato starch; cellulose, such as microcrystalline cellulose,and its derivatives, such as sodium carboxymethyl cellulose, ethylcellulose and cellulose acetate; powdered tragacanth; malt; gelatin;talc; excipients, such as cocoa butter and suppository waxes; oils, suchas peanut oil, cottonseed oil, safflower oil, sesame oil, olive oil,corn oil and soybean oil; glycols, such as propylene glycol; polyols,such as glycerin, sorbitol, mannitol and polyethylene glycol; esters,such as ethyl oleate and ethyl laurate; agar; buffering agents, such asmagnesium hydroxide and aluminum hydroxide; alginic acid; pyrogen-freewater; isotonic saline; Ringer's solution; ethyl alcohol; phosphatebuffer solutions; compressed propellant gases, such aschlorofluorocarbons and hydrofluorocarbons; and other non-toxiccompatible substances employed in pharmaceutical compositions.

Pharmaceutical compositions are typically prepared by thoroughly andintimately mixing or blending the active agent with a pharmaceuticallyacceptable carrier and one or more optional ingredients. The resultinguniformly blended mixture may then be shaped or loaded into tablets,capsules, pills, canisters, cartridges, dispensers and the like usingconventional procedures and equipment.

In one embodiment, the pharmaceutical compositions are suitable for oraladministration. Suitable compositions for oral administration may be inthe form of capsules, tablets, pills, lozenges, cachets, dragees,powders, granules; solutions or suspensions in an aqueous or non-aqueousliquid; oil-in-water or water-in-oil liquid emulsions; elixirs orsyrups; and the like; each containing a predetermined amount of theactive agent.

When intended for oral administration in a solid dosage form (capsules,tablets, pills and the like), the composition will typically comprisethe active agent and one or more pharmaceutically acceptable carriers,such as sodium citrate or dicalcium phosphate. Solid dosage forms mayalso comprise: fillers or extenders, such as starches, microcrystallinecellulose, lactose, sucrose, glucose, mannitol, and/or silicic acid;binders, such as carboxymethylcellulose, alginates, gelatin, polyvinylpyrrolidone, sucrose and/or acacia; humectants, such as glycerol;disintegrating agents, such as agar-agar, calcium carbonate, potato ortapioca starch, alginic acid, certain silicates, and/or sodiumcarbonate; solution retarding agents, such as paraffin; absorptionaccelerators, such as quaternary ammonium compounds; wetting agents,such as cetyl alcohol and/or glycerol monostearate; absorbents, such askaolin and/or bentonite clay; lubricants, such as talc, calciumstearate, magnesium stearate, solid polyethylene glycols, sodium laurylsulfate, and/or mixtures thereof; coloring agents; and buffering agents.

Release agents, wetting agents, coating agents, sweetening, flavoringand perfuming agents, preservatives and antioxidants may also be presentin the pharmaceutical compositions. Exemplary coating agents fortablets, capsules, pills and like, include those used for entericcoatings, such as cellulose acetate phthalate, polyvinyl acetatephthalate, hydroxypropyl methylcellulose phthalate, methacrylicacid-methacrylic acid ester copolymers, cellulose acetate trimellitate,carboxymethyl ethyl cellulose, hydroxypropyl methyl cellulose acetatesuccinate, and the like. Examples of pharmaceutically acceptableantioxidants include: water-soluble antioxidants, such as ascorbic acid,cysteine hydrochloride, sodium bisulfate, sodium metabisulfate sodiumsulfite and the like; oil-soluble antioxidants, such as ascorbylpalmitate, butylated hydroxyanisole, butylated hydroxytoluene, lecithin,propyl gallate, alpha-tocopherol, and the like; and metal-chelatingagents, such as citric acid, ethylenediamine tetraacetic acid, sorbitol,tartaric acid, phosphoric acid, and the like.

Compositions may also be formulated to provide slow or controlledrelease of the active agent using, by way of example, hydroxypropylmethyl cellulose in varying proportions or other polymer matrices,liposomes and/or microspheres. In addition, the pharmaceuticalcompositions of the invention may contain opacifying agents and may beformulated so that they release the active agent only, orpreferentially, in a certain portion of the gastrointestinal tract,optionally, in a delayed manner. Examples of embedding compositionswhich can be used include polymeric substances and waxes. The activeagent can also be in micro-encapsulated form, optionally with one ormore of the above-described excipients.

Suitable liquid dosage forms for oral administration include, by way ofillustration, pharmaceutically acceptable emulsions, microemulsions,solutions, suspensions, syrups and elixirs. Liquid dosage formstypically comprise the active agent and an inert diluent, such as, forexample, water or other solvents, solubilizing agents and emulsifiers,such as ethyl alcohol, isopropyl alcohol, ethyl carbonate, ethylacetate, benzyl alcohol, benzyl benzoate, propylene glycol, 1,3-butyleneglycol, oils (for example, cottonseed, groundnut, corn, germ, olive,castor and sesame oils), glycerol, tetrahydrofuryl alcohol, polyethyleneglycols and fatty acid esters of sorbitan, and mixtures thereof.Suspensions may contain suspending agents such as, for example,ethoxylated isostearyl alcohols, polyoxyethylene sorbitol and sorbitanesters, microcrystalline cellulose, aluminium metahydroxide, bentonite,agar-agar and tragacanth, and mixtures thereof.

When intended for oral administration, the pharmaceutical compositionsof the invention may be packaged in a unit dosage form. The term “unitdosage form” refers to a physically discrete unit suitable for dosing apatient, that is, each unit containing a predetermined quantity of theactive agent calculated to produce the desired therapeutic effect eitheralone or in combination with one or more additional units. For example,such unit dosage forms may be capsules, tablets, pills, and the like.

In another embodiment, the compositions of the invention are suitablefor inhaled administration, and will typically be in the form of anaerosol or a powder. Such compositions are generally administered usingwell-known delivery devices, such as a nebulizer, dry powder, ormetered-dose inhaler. Nebulizer devices produce a stream of highvelocity air that causes the composition to spray as a mist that iscarried into a patient's respiratory tract. An exemplary nebulizerformulation comprises the active agent dissolved in a carrier to form asolution, or micronized and combined with a carrier to form a suspensionof micronized particles of respirable size. Dry powder inhalersadminister the active agent as a free-flowing powder that is dispersedin a patient's air-stream during inspiration. An exemplary dry powderformulation comprises the active agent dry-blended with an excipientsuch as lactose, starch, mannitol, dextrose, polylactic acid,polylactide-co-glycolide, and combinations thereof. Metered-doseinhalers discharge a measured amount of the active agent usingcompressed propellant gas. An exemplary metered-dose formulationcomprises a solution or suspension of the active agent in a liquefiedpropellant, such as a chlorofluorocarbon or hydrofluoroalkane. Optionalcomponents of such formulations include co-solvents, such as ethanol orpentane, and surfactants, such as sorbitan trioleate, oleic acid,lecithin, glycerin, and sodium lauryl sulfate. Such compositions aretypically prepared by adding chilled or pressurized hydrofluoroalkane toa suitable container containing the active agent, ethanol (if present)and the surfactant (if present). To prepare a suspension, the activeagent is micronized and then combined with the propellant.Alternatively, a suspension formulation can be prepared by spray dryinga coating of surfactant on micronized particles of the active agent. Theformulation is then loaded into an aerosol canister, which forms aportion of the inhaler.

Compounds of the invention can also be administered parenterally (forexample, by subcutaneous, intravenous, intramuscular, or intraperitonealinjection). For such administration, the active agent is provided in asterile solution, suspension, or emulsion. Exemplary solvents forpreparing such formulations include water, saline, low molecular weightalcohols such as propylene glycol, polyethylene glycol, oils, gelatin,fatty acid esters such as ethyl oleate, and the like. Parenteralformulations may also contain one or more anti-oxidants, solubilizers,stabilizers, preservatives, wetting agents, emulsifiers, and dispersingagents. Surfactants, additional stabilizing agents or pH-adjustingagents (acids, bases or buffers) and anti-oxidants are particularlyuseful to provide stability to the formulation, for example, to minimizeor avoid hydrolysis of ester and amide linkages, or dimerization ofthiols that may be present in the compound. These formulations may berendered sterile by use of a sterile injectable medium, a sterilizingagent, filtration, irradiation, or heat. In one particular embodiment,the parenteral formulation comprises an aqueous cyclodextrin solution asthe pharmaceutically acceptable carrier. Suitable cyclodextrins includecyclic molecules containing six or more α-D-glucopyranose units linkedat the 1,4 positions by a linkages as in amylase, β-cyclodextrin orcycloheptaamylose. Exemplary cyclodextrins include cyclodextrinderivatives such as hydroxypropyl and sulfobutyl ether cyclodextrinssuch as hydroxypropyl-β-cyclodextrin and sulfobutyl etherβ-cyclodextrin. Exemplary buffers for such formulations includecarboxylic acid-based buffers such as citrate, lactate and maleatebuffer solutions.

Compounds of the invention can also be administered transdermally usingknown transdermal delivery systems and excipients. For example, thecompound can be admixed with permeation enhancers, such as propyleneglycol, polyethylene glycol monolaurate, azacycloalkan-2-ones and thelike, and incorporated into a patch or similar delivery system.Additional excipients including gelling agents, emulsifiers and buffers,may be used in such transdermal compositions if desired.

Secondary Agents

The compounds of the invention may be useful as the sole treatment of adisease or may be combined with one or more additional therapeuticagents in order to obtain the desired therapeutic effect. Thus, in oneembodiment, pharmaceutical compositions of the invention contain otherdrugs that are co-administered with a compound of the invention. Forexample, the composition may further comprise one or more drugs (alsoreferred to as “secondary agents(s)”). Such therapeutic agents are wellknown in the art, and include adenosine receptor antagonists,α-adrenergic receptor antagonists, β₁-adrenergic receptor antagonists,β₂-adrenergic receptor agonists, dual-acting β-adrenergic receptorantagonist/α₁-receptor antagonists, advanced glycation end productbreakers, aldosterone antagonists, aldosterone synthase inhibitors,aminopeptidase N inhibitors, androgens, angiotensin-converting enzymeinhibitors and dual-acting angiotensin-converting enzyme/neprilysininhibitors, angiotensin-converting enzyme 2 activators and stimulators,angiotensin-II vaccines, anticoagulants, anti-diabetic agents,antidiarrheal agents, anti-glaucoma agents, anti-lipid agents,antinociceptive agents, anti-thrombotic agents, AT₁ receptor antagonistsand dual-acting AT₁ receptor antagonist/neprilysin inhibitors andmultifunctional angiotensin receptor blockers, bradykinin receptorantagonists, calcium channel blockers, chymase inhibitors, digoxin,diuretics, dopamine agonists, endothelin converting enzyme inhibitors,endothelin receptor antagonists, HMG-CoA reductase inhibitors,estrogens, estrogen receptor agonists and/or antagonists, monoaminereuptake inhibitors, muscle relaxants, natriuretic peptides and theiranalogs, natriuretic peptide clearance receptor antagonists, neprilysininhibitors, nitric oxide donors, non-steroidal anti-inflammatory agents,N-methyl d-aspartate receptor antagonists, opioid receptor agonists,phosphodiesterase inhibitors, prostaglandin analogs, prostaglandinreceptor agonists, renin inhibitors, selective serotonin reuptakeinhibitors, sodium channel blocker, soluble guanylate cyclasestimulators and activators, tricyclic antidepressants, vasopressinreceptor antagonists, and combinations thereof. Specific examples ofthese agents are detailed herein.

Accordingly, in yet another aspect of the invention, a pharmaceuticalcomposition comprises a compound of the invention, a second activeagent, and a pharmaceutically acceptable carrier. Third, fourth etc.active agents may also be included in the composition. In combinationtherapy, the amount of compound of the invention that is administered,as well as the amount of secondary agents, may be less than the amounttypically administered in monotherapy.

Compounds of the invention may be physically mixed with the secondactive agent to form a composition containing both agents; or each agentmay be present in separate and distinct compositions which areadministered to the patient simultaneously or at separate times. Forexample, a compound of the invention can be combined with a secondactive agent using conventional procedures and equipment to form acombination of active agents comprising a compound of the invention anda second active agent. Additionally, the active agents may be combinedwith a pharmaceutically acceptable carrier to form a pharmaceuticalcomposition comprising a compound of the invention, a second activeagent and a pharmaceutically acceptable carrier. In this embodiment, thecomponents of the composition are typically mixed or blended to create aphysical mixture. The physical mixture is then administered in atherapeutically effective amount using any of the routes describedherein.

Alternatively, the active agents may remain separate and distinct beforeadministration to the patient. In this embodiment, the agents are notphysically mixed together before administration but are administeredsimultaneously or at separate times as separate compositions. Suchcompositions can be packaged separately or may be packaged together in akit. When administered at separate times, the secondary agent willtypically be administered less than 24 hours after administration of thecompound of the invention, ranging anywhere from concurrent withadministration of the compound of the invention to about 24 hourspost-dose. This is also referred to as sequential administration. Thus,a compound of the invention can be orally administered simultaneously orsequentially with another active agent using two tablets, with onetablet for each active agent, where sequential may mean beingadministered immediately after administration of the compound of theinvention or at some predetermined time later (for example, one hourlater or three hours later). It is also contemplated that the secondaryagent may be administered more than 24 hours after administration of thecompound of the invention. Alternatively, the combination may beadministered by different routes of administration, that is, one orallyand the other by inhalation.

In one embodiment, the kit comprises a first dosage form comprising acompound of the invention and at least one additional dosage formcomprising one or more of the secondary agents set forth herein, inquantities sufficient to carry out the methods of the invention. Thefirst dosage form and the second (or third, etc.) dosage form togethercomprise a therapeutically effective amount of active agents for thetreatment or prevention of a disease or medical condition in a patient.

Secondary agent(s), when included, are present in a therapeuticallyeffective amount such that they are typically administered in an amountthat produces a therapeutically beneficial effect when co-administeredwith a compound of the invention. The secondary agent can be in the formof a pharmaceutically acceptable salt, solvate, optically purestereoisomer, and so forth. The secondary agent may also be in the formof a prodrug, for example, a compound having a carboxylic acid groupthat has been esterified. Thus, secondary agents listed herein areintended to include all such forms, and are commercially available orcan be prepared using conventional procedures and reagents.

In one embodiment, compounds of the invention are administered incombination with an adenosine receptor antagonist, representativeexamples of which include, but are not limited to, naxifylline,rolofylline, SLV-320, theophylline, and tonapofylline.

In one embodiment, compounds of the invention are administered incombination with an α-adrenergic receptor antagonist, representativeexamples of which include, but are not limited to, doxazosin, prazosin,tamsulosin, and terazosin.

Compounds of the invention may also be administered in combination witha β₁-adrenergic receptor antagonist (“β₁-blockers”). Representativeβ₁-blockers include, but are not limited to, acebutolol, alprenolol,amosulalol, arotinolol, atenolol, befunolol, betaxolol, bevantolol,bisoprolol, bopindolol, bucindolol, bucumolol, bufetolol, bufuralol,bunitrolol, bupranolol, bubridine, butofilolol, carazolol, carteolol,carvedilol, celiprolol, cetamolol, cloranolol, dilevalol, epanolol,esmolol, indenolol, labetolol, levobunolol, mepindolol, metipranolol,metoprolol such as metoprolol succinate and metoprolol tartrate,moprolol, nadolol, nadoxolol, nebivalol, nipradilol, oxprenolol,penbutolol, perbutolol, pindolol, practolol, pronethalol, propranolol,sotalol, sufinalol, talindol, tertatolol, tilisolol, timolol,toliprolol, xibenolol, and combinations thereof. In one particularembodiment, the β₁-antagonist is selected from atenolol, bisoprolol,metoprolol, propranolol, sotalol, and combinations thereof. Typically,the β₁-blocker will be administered in an amount sufficient to providefrom about 2-900 mg per dose.

In one embodiment, compounds of the invention are administered incombination with a β₂-adrenergic receptor agonist, representativeexamples of which include, but are not limited to, albuterol,bitolterol, fenoterol, formoterol, indacaterol, isoetharine,levalbuterol, metaproterenol, pirbuterol, salbutamol, salmefamol,salmeterol, terbutaline, vilanterol, and the like Typically, theβ₂-adrenergic receptor agonist will be administered in an amountsufficient to provide from about 0.05-500 μg per dose.

In one embodiment, compounds of the invention are administered incombination with an advanced glycation end product (AGE) breaker,examples of which include, by way of illustration and not limitation,alagebrium (or ALT-711), and TRC4149.

In another embodiment, compounds of the invention are administered incombination with an aldosterone antagonist, representative examples ofwhich include, but are not limited to, eplerenone, spironolactone, andcombinations thereof. Typically, the aldosterone antagonist will beadministered in an amount sufficient to provide from about 5-300 mg perday.

In one embodiment, compounds of the invention are administered incombination with an aminopeptidase N or dipeptidyl peptidase IIIinhibitor, examples of which include, by way of illustration and notlimitation, bestatin and PC18 (2-amino-4-methylsulfonyl butane thiol,methionine thiol).

Compounds of the invention can also be administered in combination withan angiotensin-converting enzyme (ACE) inhibitor. Representative ACEinhibitors include, but are not limited to, accupril, alacepril,benazepril, benazeprilat, captopril, ceranapril, cilazapril, delapril,enalapril, enalaprilat, fosinopril, fosinoprilat, imidapril, lisinopril,moexipril, monopril, moveltipril, pentopril, perindopril, quinapril,quinaprilat, ramipril, ramiprilat, saralasin acetate, spirapril,temocapril, trandolapril, zofenopril, and combinations thereof.

In a particular embodiment, the ACE inhibitor is selected from:benazepril, captopril, enalapril, lisinopril, ramipril, and combinationsthereof. Typically, the ACE inhibitor will be administered in an amountsufficient to provide from about 1-150 mg per day. In anotherembodiment, compounds of the invention are administered in combinationwith a dual-acting angiotensin-converting enzyme/neprilysin (ACE/NEP)inhibitor, examples of which include, but are not limited to: AVE-0848((4S,7S,12bR)-7-[3-methyl-2(S)-sulfanylbutyramido]-6-oxo-1,2,3,4,6,7,8,12b-octahydropyrido[2,1-a][2]-benzazepine-4-carboxylicacid); AVE-7688 (ilepatril) and its parent compound; BMS-182657(2-[2-oxo-3(S)-[3-phenyl-2(S)-sulfanylpropionamido]-2,3,4,5-tetrahydro-1H-1-benzazepin-1-yl]aceticacid); CGS-35601(N-[1-[4-methyl-2(S)-sulfanylpentanamido]cyclopentyl-carbonyl]-L-tryptophan);fasidotril; fasidotrilate; enalaprilat; ER-32935((3R,6S,9aR)-6-[3(S)-methyl-2(S)-sulfanylpentanamido]-5-oxoperhydrothiazolo[3,2-a]azepine-3-carboxylicacid); gempatrilat; MDL-101264((4S,7S,12bR)-7-[2(S)-(2-morpholinoacetylthio)-3-phenylpropionamido]-6-oxo-1,2,3,4,6,7,8,12b-octahydropyrido[2,1-a][2]benzazepine-4-carboxylicacid); MDL-101287 ([4S-[4α,7α(R*),12bβ]]-7-[2-(carboxymethyl)-3-phenylpropionamido]-6-oxo-1,2,3,4,6,7,8,12b-octahydropyrido[2,1-a][2]benzazepine-4-carboxylicacid); omapatrilat; RB-105(N-[2(S)-(mercaptomethyl)-3(R)-phenylbutyl]-L-alanine); sampatrilat;SA-898((2R,4R)—N-[2-(2-hydroxyphenyl)-3-(3-mercaptopropionyl)thiazolidin-4-ylcarbonyl]-L-phenylalanine);Sch-50690(N-[1(S)-carboxy-2-[N2-(methanesulfonyl)-L-lysylamino]ethyl]-L-valyl-L-tyrosine);and combinations thereof, may also be included. In one particularembodiment, the ACE/NEP inhibitor is selected from: AVE-7688,enalaprilat, fasidotril, fasidotrilate, omapatrilat, sampatrilat, andcombinations thereof.

In one embodiment, compounds of the invention are administered incombination with an angiotensin-converting enzyme 2 (ACE2) activator orstimulator.

In one embodiment, compounds of the invention are administered incombination with an angiotensin-II vaccine, examples of which include,but are not limited to ATR12181 and CYT006-AngQb.

In one embodiment, compounds of the invention are administered incombination with an anticoagulant, representative examples of whichinclude, but are not limited to: coumarins such as warfarin; heparin;and direct thrombin inhibitors such as argatroban, bivalirudin,dabigatran, and lepirudin.

In yet another embodiment, compounds of the invention are administeredin combination with an anti-diabetic agent. Representative anti-diabeticagents include injectable drugs as well as orally effective drugs, andcombinations thereof. Examples of injectable drugs include, but are notlimited to, insulin and insulin derivatives. Examples of orallyeffective drugs include, but are not limited to: biguanides such asmetformin; glucagon antagonists; α-glucosidase inhibitors such asacarbose and miglitol; dipeptidyl peptidase IV inhibitors (DPP-IVinhibitors) such as alogliptin, denagliptin, linagliptin, saxagliptin,sitagliptin, and vildagliptin; meglitinides such as repaglinide;oxadiazolidinediones; sulfonylureas such as chlorpropamide, glimepiride,glipizide, glyburide, and tolazamide; thiazolidinediones such aspioglitazone and rosiglitazone; and combinations thereof.

In another embodiment, compounds of the invention are administered incombination with antidiarrheal treatments. Representative treatmentoptions include, but are not limited to, oral rehydration solutions(ORS), loperamide, diphenoxylate, and bismuth subsalicylate.

In yet another embodiment, a compound of the invention is administeredin combination with an anti-glaucoma agent. Representative anti-glaucomaagents include, but are not limited to: α-adrenergic agonists such asbrimonidine; β₁-adrenergic receptor antagonists; topical β₁-blockerssuch as betaxolol, levobunolol, and timolol; carbonic anhydraseinhibitors such as acetazolamide, brinzolamide, or dorzolamide;cholinergic agonists such as cevimeline and DMXB-anabaseine; epinephrinecompounds; miotics such as pilocarpine; and prostaglandin analogs.

In yet another embodiment, compounds of the invention are administeredin combination with an anti-lipid agent. Representative anti-lipidagents include, but are not limited to: cholesteryl ester transferprotein inhibitors (CETPs) such as anacetrapib, dalcetrapib, andtorcetrapib; statins such as atorvastatin, fluvastatin, lovastatin,pravastatin, rosuvastatin and simvastatin; and combinations thereof.

In one embodiment, compounds of the invention are administered incombination with an anti-thrombotic agent. Representativeanti-thrombotic agents include, but are not limited to: aspirin;anti-platelet agents such as clopidogrel, prasugrel, and ticlopidine;heparin, and combinations thereof.

In one embodiment, compounds of the invention are administered incombination with an AT₁ receptor antagonist, also known as angiotensinII type 1 receptor blockers (ARBs). Representative ARBs include, but arenot limited to, abitesartan, azilsartan (e.g., azilsartan medoxomil),benzyllosartan, candesartan, candesartan cilexetil, elisartan,embusartan, enoltasosartan, eprosartan, EXP3174, fonsartan, forasartan,glycyllosartan, irbesartan, isoteoline, losartan, medoxomil,milfasartan, olmesartan (e.g., olmesartan medoxomil), opomisartan,pratosartan, ripisartan, saprisartan, saralasin, sarmesin, TAK-591,tasosartan, telmisartan, valsartan, zolasartan, and combinationsthereof. In a particular embodiment, the ARB is selected from azilsartanmedoxomil, candesartan cilexetil, eprosartan, irbesartan, losartan,olmesartan medoxomil, saprisartan, tasosartan, telmisartan, valsartan,and combinations thereof. Exemplary salts and/or prodrugs includecandesartan cilexetil, eprosartan mesylate, losartan potassium salt, andolmesartan medoxomil. Typically, the ARB will be administered in anamount sufficient to provide from about 4-600 mg per dose, withexemplary daily dosages ranging from 20-320 mg per day.

Compounds of the invention may also be administered in combination witha dual-acting agent, such as an AT₁ receptor antagonist/neprilysininhibitor (ARB/NEP) inhibitor, examples of which include, but are notlimited to, compounds described in U.S. Publication Nos. 2008/0269305and 2009/0023228, both to Allegretti et al. filed on Apr. 23, 2008, suchas the compound,4′-{2-ethoxy-4-ethyl-5-[((S)-2-mercapto-4-methylpentanoylamino)-methyl]imidazol-1-ylmethyl}-3′-fluorobiphenyl-2-carboxylicacid.

Compounds of the invention may also be administered in combination withmultifunctional angiotensin receptor blockers as described in Kurtz &Klein (2009) Hypertension Research 32:826-834.

In one embodiment, compounds of the invention are administered incombination with a bradykinin receptor antagonist, for example,icatibant (HOE-140). It is expected that this combination therapy maypresent the advantage of preventing angioedema or other unwantedconsequences of elevated bradykinin levels.

In one embodiment, compounds of the invention are administered incombination with a calcium channel blocker. Representative calciumchannel blockers include, but are not limited to, amlodipine, anipamil,aranipine, bamidipine, bencyclane, benidipine, bepridil, clentiazem,cilnidipine, cinnarizine, diltiazem, efonidipine, elgodipine, etafenone,felodipine, fendiline, flunarizine, gallopamil, isradipine, lacidipine,lercanidipine, lidoflazine, lomerizine, manidipine, mibefradil,nicardipine, nifedipine, niguldipine, niludipine, nilvadipine,nimodipine, nisoldipine, nitrendipine, nivaldipine, perhexiline,prenylamine, ryosidine, semotiadil, terodiline, tiapamil, verapamil, andcombinations thereof. In a particular embodiment, the calcium channelblocker is selected from amlodipine, bepridil, diltiazem, felodipine,isradipine, lacidipine, nicardipine, nifedipine, niguldipine,niludipine, nimodipine, nisoldipine, ryosidine, verapamil, andcombinations thereof. Typically, the calcium channel blocker will beadministered in an amount sufficient to provide from about 2-500 mg perdose.

In one embodiment, compounds of the invention are administered incombination with a chymase inhibitor, such as TPC-806 and2-(5-formylamino-6-oxo-2-phenyl-1,6-dihydropyrimidine-1-yl)-N-[{3,4-dioxo-1-phenyl-7-(2-pyridyloxy)}-2-heptyl]acetamide(NK3201).

In one embodiment, compounds of the invention are administered incombination with a diuretic. Representative diuretics include, but arenot limited to: carbonic anhydrase inhibitors such as acetazolamide anddichlorphenamide; loop diuretics, which include sulfonamide derivativessuch as acetazolamide, ambuside, azosemide, bumetanide, butazolamide,chloraminophenamide, clofenamide, clopamide, clorexolone, disulfamide,ethoxzolamide, furosemide, mefruside, methazolamide, piretanide,torsemide, tripamide, and xipamide, as well as non-sulfonamide diureticssuch as ethacrynic acid and other phenoxyacetic acid compounds such astienilic acid, indacrinone and quincarbate; osmotic diuretics such asmannitol; potassium-sparing diuretics, which include aldosteroneantagonists such as spironolactone, and Na⁺ channel inhibitors such asamiloride and triamterene; thiazide and thiazide-like diuretics such asalthiazide, bendroflumethiazide, benzylhydrochlorothiazide,benzthiazide, buthiazide, chlorthalidone, chlorothiazide,cyclopenthiazide, cyclothiazide, epithiazide, ethiazide, fenquizone,flumethiazide, hydrochlorothiazide, hydroflumethiazide, indapamide,methylclothiazide, meticrane, metolazone, paraflutizide, polythiazide,quinethazone, teclothiazide, and trichloromethiazide; and combinationsthereof. In a particular embodiment, the diuretic is selected fromamiloride, bumetanide, chlorothiazide, chlorthalidone, dichlorphenamide,ethacrynic acid, furosemide, hydrochlorothiazide, hydroflumethiazide,indapamide, methylclothiazide, metolazone, torsemide, triamterene, andcombinations thereof. The diuretic will be administered in an amountsufficient to provide from about 5-50 mg per day, more typically 6-25 mgper day, with common dosages being 6.25 mg, 12.5 mg or 25 mg per day.

Compounds of the invention may also be administered in combination withan endothelin converting enzyme (ECE) inhibitor, examples of whichinclude, but are not limited to, phosphoramidon, CGS 26303, andcombinations thereof.

In a particular embodiment, compounds of the invention are administeredin combination with an endothelin receptor antagonist. Representativeendothelin receptor antagonists include, but are not limited to:selective endothelin receptor antagonists that affect endothelin Areceptors, such as avosentan, ambrisentan, atrasentan, BQ-123,clazosentan, darusentan, sitaxentan, and zibotentan; and dual endothelinreceptor antagonists that affect both endothelin A and B receptors, suchas bosentan, macitentan, tezosentan).

In yet another embodiment, a compound of the invention is administeredin combination with one or more HMG-CoA reductase inhibitors, which arealso known as statins. Representative statins include, but are notlimited to, atorvastatin, fluvastatin, lovastatin, pitavastatin,pravastatin, rosuvastatin and simvastatin.

In one embodiment, compounds of the invention are administered incombination with a monoamine reuptake inhibitor, examples of whichinclude, by way of illustration and not limitation, norepinephrinereuptake inhibitors such as atomoxetine, buproprion and the buproprionmetabolite hydroxybuproprion, maprotiline, reboxetine, and viloxazine;selective serotonin reuptake inhibitors (SSRIs) such as citalopram andthe citalopram metabolite desmethylcitalopram, dapoxetine, escitalopram(e.g., escitalopram oxalate), fluoxetine and the fluoxetine desmethylmetabolite norfluoxetine, fluvoxamine (e.g., fluvoxamine maleate),paroxetine, sertraline and the sertraline metabolite demethylsertraline;dual serotonin-norepinephrine reuptake inhibitors (SNRIs) such asbicifadine, duloxetine, milnacipran, nefazodone, and venlafaxine; andcombinations thereof.

In another embodiment, compounds of the invention are administered incombination with a muscle relaxant, examples of which include, but arenot limited to: carisoprodol, chlorzoxazone, cyclobenzaprine,diflunisal, metaxalone, methocarbamol, and combinations thereof.

In one embodiment, compounds of the invention are administered incombination with a natriuretic peptide or analog, examples of whichinclude but are not limited to: carperitide, CD-NP (Nile Therapeutics),CU-NP, nesiritide, PL-3994 (Palatin Technologies, Inc.), ularitide,cenderitide, and compounds described in Ogawa et al (2004) J. Biol.Chem. 279:28625-31. These compounds are also referred to as natriureticpeptide receptor-A (NPR-A) agonists. In another embodiment, compounds ofthe invention are administered in combination with a natriuretic peptideclearance receptor (NPR-C) antagonist such as SC-46542, cANF (4-23), andAP-811 (Veale (2000) Bioorg Med Chem Lett 10:1949-52). For example,AP-811 has shown synergy when combined with the NEP inhibitor, thiorphan(Wegner (1995) Clin. Exper. Hypert. 17:861-876).

In another embodiment, compounds of the invention are administered incombination with a neprilysin (NEP) inhibitor. Representative NEPinhibitors include, but are not limited to: AHU-377; candoxatril;candoxatrilat; dexecadotril((+)-N-[2(R)-(acetylthiomethyl)-3-phenylpropionyl]glycine benzyl ester);CGS-24128(3-[3-(biphenyl-4-yl)-2-(phosphonomethylamino)propionamido]propionicacid); CGS-24592((S)-3-[3-(biphenyl-4-yl)-2-(phosphonomethylamino)propionamido]propionicacid); CGS-25155(N-[9(R)-(acetylthiomethyl)-10-oxo-1-azacyclodecan-2(S)-ylcarbonyl]-4(R)-hydroxy-L-prolinebenzyl ester); 3-(1-carbamoylcyclohexyl)propionic acid derivativesdescribed in WO 2006/027680 to Hepworth et al. (Pfizer Inc.); JMV-390-1(2(R)-benzyl-3-(N-hydroxycarbamoyl)propionyl-L-isoleucyl-L-leucine);ecadotril; phosphoramidon; retrothiorphan; RU-42827(2-(mercaptomethyl)-N-(4-pyridinyl)benzenepropionamide); RU-44004(N-(4-morpholinyl)-3-phenyl-2-(sulfanylmethyl)propionamide); SCH-32615((S)—N—[N-(1-carboxy-2-phenylethyl)-L-phenylalanyl]-β-alanine) and itsprodrug SCH-34826((S)—N—[N-[1-[[(2,2-dimethyl-1,3-dioxolan-4-yl)methoxy]carbonyl]-2-phenylethyl]-L-phenylalanyl]-β-alanine);sialorphin; SCH-42495(N-[2(S)-(acetylsulfanylmethyl)-3-(2-methylphenyl)propionyl]-L-methionineethyl ester); spinorphin; SQ-28132(N-[2-(mercaptomethyl)-1-oxo-3-phenylpropyl]leucine); SQ-28603(N-[2-(mercaptomethyl)-1-oxo-3-phenylpropyl]-β-alanine); SQ-29072(7-[[2-(mercaptomethyl)-1-oxo-3-phenylpropyl]amino]heptanoic acid);thiorphan and its prodrug racecadotril; UK-69578(cis-4-[[[1-[2-carboxy-3-(2-methoxyethoxy)propyl]cyclopentyl]carbonyl]amino]cyclohexanecarboxylicacid); UK-447,841(2-{1-[3-(4-chlorophenyl)propylcarbamoyl]-cyclopentylmethyl}-4-methoxybutyricacid); UK-505,749((R)-2-methyl-3-{1-[3-(2-methylbenzothiazol-6-yl)propylcarbamoyl]cyclopentyl}propionicacid); 5-biphenyl-4-yl-4-(3-carboxypropionylamino)-2-methylpentanoicacid and 5-biphenyl-4-yl-4-(3-carboxypropionylamino)-2-methylpentanoicacid ethyl ester (WO 2007/056546); daglutril[(3S,2′R)-3-{1-[2′-(ethoxycarbonyl)-4′-phenylbutyl]-cyclopentan-1-carbonylamino}-2,3,4,5-tetrahydro-2-oxo-1H-1-benzazepine-1-aceticacid] described in WO 2007/106708 to Khder et al. (Novartis AG); andcombinations thereof. In a particular embodiment, the NEP inhibitor isselected from AHU-377, candoxatril, candoxatrilat, CGS-24128,phosphoramidon, SCH-32615, SCH-34826, SQ-28603, thiorphan, andcombinations thereof. In a particular embodiment, the NEP inhibitor is acompound such as daglutril or CGS-26303([N-[2-(biphenyl-4-yl)-1(S)-(1H-tetrazol-5-yl)ethyl]amino]methylphosphonicacid), which have activity both as inhibitors of the endothelinconverting enzyme (ECE) and of NEP. Other dual acting ECE/NEP compoundscan also be used. The NEP inhibitor will be administered in an amountsufficient to provide from about 20-800 mg per day, with typical dailydosages ranging from 50-700 mg per day, more commonly 100-600 or 100-300mg per day.

In one embodiment, compounds of the invention are administered incombination with a nitric oxide donor, examples of which include, butare not limited to nicorandil; organic nitrates such as pentaerythritoltetranitrate; and sydnonimines such as linsidomine and molsidomine.

In yet another embodiment, compounds of the invention are administeredin combination with a non-steroidal anti-inflammatory agent (NSAID).Representative NSAIDs include, but are not limited to: acemetacin,acetyl salicylic acid, alclofenac, alminoprofen, amfenac, amiprilose,aloxiprin, anirolac, apazone, azapropazone, benorilate, benoxaprofen,bezpiperylon, broperamole, bucloxic acid, carprofen, clidanac,diclofenac, diflunisal, diftalone, enolicam, etodolac, etoricoxib,fenbufen, fenclofenac, fenclozic acid, fenoprofen, fentiazac, feprazone,flufenamic acid, flufenisal, fluprofen, flurbiprofen, furofenac,ibufenac, ibuprofen, indomethacin, indoprofen, isoxepac, isoxicam,ketoprofen, ketorolac, lofemizole, lomoxicam, meclofenamate,meclofenamic acid, mefenamic acid, meloxicam, mesalamine, miroprofen,mofebutazone, nabumetone, naproxen, niflumic acid, oxaprozin, oxpinac,oxyphenbutazone, phenylbutazone, piroxicam, pirprofen, pranoprofen,salsalate, sudoxicam, sulfasalazine, sulindac, suprofen, tenoxicam,tiopinac, tiaprofenic acid, tioxaprofen, tolfenamic acid, tolmetin,triflumidate, zidometacin, zomepirac, and combinations thereof. In aparticular embodiment, the NSAID is selected from etodolac,flurbiprofen, ibuprofen, indomethacin, ketoprofen, ketorolac, meloxicam,naproxen, oxaprozin, piroxicam, and combinations thereof.

In one embodiment, compounds of the invention are administered incombination with an N-methyl d-aspartate (NMDA) receptor antagonist,examples of which include, by way of illustration and not limitation,amantadine, dextromethorphan, dextropropoxyphene, ketamine,ketobemidone, memantine, methadone, and so forth.

In still another embodiment, compounds of the invention are administeredin combination with an opioid receptor agonist (also referred to asopioid analgesics). Representative opioid receptor agonists include, butare not limited to: buprenorphine, butorphanol, codeine, dihydrocodeine,fentanyl, hydrocodone, hydromorphone, levallorphan, levorphanol,meperidine, methadone, morphine, nalbuphine, nalmefene, nalorphine,naloxone, naltrexone, nalorphine, oxycodone, oxymorphone, pentazocine,propoxyphene, tramadol, and combinations thereof. In certainembodiments, the opioid receptor agonist is selected from codeine,dihydrocodeine, hydrocodone, hydromorphone, morphine, oxycodone,oxymorphone, tramadol, and combinations thereof.

In a particular embodiment, compounds of the invention are administeredin combination with a phosphodiesterase (PDE) inhibitor, particularly aPDE-V inhibitor. Representative PDE-V inhibitors include, but are notlimited to, avanafil, lodenafil, mirodenafil, sildenafil (Revatio®),tadalafil (Adcirca®), vardenafil (Levitra®), and udenafil.

In another embodiment, compounds of the invention are administered incombination with a prostaglandin analog (also referred to as prostanoidsor prostacyclin analogs). Representative prostaglandin analogs include,but are not limited to, beraprost sodium, bimatoprost, epoprostenol,iloprost, latanoprost, tafluprost, travoprost, and treprostinil, withbimatoprost, latanoprost, and tafluprost being of particular interest.

In yet another embodiment, compounds of the invention are administeredin combination with a prostaglandin receptor agonist, examples of whichinclude, but are not limited to, bimatoprost, latanoprost, travoprost,and so forth.

Compounds of the invention may also be administered in combination witha renin inhibitor, examples of which include, but are not limited to,aliskiren, enalkiren, remikiren, and combinations thereof.

In another embodiment, compounds of the invention are administered incombination with a selective serotonin reuptake inhibitor (SSRI).Representative SSRIs include, but are not limited to: citalopram and thecitalopram metabolite desmethyl-citalopram, dapoxetine, escitalopram(e.g., escitalopram oxalate), fluoxetine and the fluoxetine desmethylmetabolite norfluoxetine, fluvoxamine (e.g., fluvoxamine maleate),paroxetine, sertraline and the sertraline metabolite demethylsertraline,and combinations thereof.

In one embodiment, compounds of the invention are administered incombination with a 5-HT_(1D) serotonin receptor agonist, examples ofwhich include, by way of illustration and not limitation, triptans suchas almotriptan, avitriptan, eletriptan, frovatriptan, naratriptan,rizatriptan, sumatriptan, and zolmitriptan.

In one embodiment, compounds of the invention are administered incombination with a sodium channel blocker, examples of which include, byway of illustration and not limitation, carbamazepine, fosphenytoin,lamotrigine, lidocaine, mexiletine, oxcarbazepine, phenytoin, andcombinations thereof.

In one embodiment, compounds of the invention are administered incombination with a soluble guanylate cyclase stimulator or activator,examples of which include, but are not limited to ataciguat, riociguat,and combinations thereof.

In one embodiment, compounds of the invention are administered incombination with a tricyclic antidepressant (TCA), examples of whichinclude, by way of illustration and not limitation, amitriptyline,amitriptylinoxide, butriptyline, clomipramine, demexiptiline,desipramine, dibenzepin, dimetacrine, dosulepin, doxepin, imipramine,imipraminoxide, lofepramine, melitracen, metapramine, nitroxazepine,nortriptyline, noxiptiline, pipofezine, propizepine, protriptyline,quinupramine, and combinations thereof.

In one embodiment, compounds of the invention are administered incombination with a vasopressin receptor antagonist, examples of whichinclude, by way of illustration and not limitation, conivaptan andtolvaptan.

Combined secondary therapeutic agents may also be helpful in furthercombination therapy with compounds of the invention. For example,compounds of the invention can be combined with a diuretic and an ARB,or a calcium channel blocker and an ARB, or a diuretic and an ACEinhibitor, or a calcium channel blocker and a statin. Specific examplesinclude, a combination of the ACE inhibitor enalapril (in the maleatesalt form) and the diuretic hydrochlorothiazide, which is sold under themark Vaseretic®, or a combination of the calcium channel blockeramlodipine (in the besylate salt form) and the ARB olmesartan (in themedoxomil prodrug form), or a combination of a calcium channel blockerand a statin, all may also be used with the compounds of the invention.Other therapeutic agents such as α₂-adrenergic receptor agonists andvasopressin receptor antagonists may also be helpful in combinationtherapy. Exemplary α₂-adrenergic receptor agonists include clonidine,dexmedetomidine, and guanfacine.

The following formulations illustrate representative pharmaceuticalcompositions of the invention.

Exemplary Hard Gelatin Capsules for Oral Administration

A compound of the invention (50 g), 440 g spray-dried lactose and 10 gmagnesium stearate are thoroughly blended. The resulting composition isthen loaded into hard gelatin capsules (500 mg of composition percapsule). Alternately, a compound of the invention (20 mg) is thoroughlyblended with starch (89 mg), microcrystalline cellulose (89 mg) andmagnesium stearate (2 mg). The mixture is then passed through a No. 45mesh U.S. sieve and loaded into a hard gelatin capsule (200 mg ofcomposition per capsule).

Alternately, a compound of the invention (30 g), a secondary agent (20g), 440 g spray-dried lactose and 10 g magnesium stearate are thoroughlyblended, and processed as described above.

Exemplary Gelatin Capsule Formulation for Oral Administration

A compound of the invention (100 mg) is thoroughly blended withpolyoxyethylene sorbitan monooleate (50 mg) and starch powder (250 mg).The mixture is then loaded into a gelatin capsule (400 mg of compositionper capsule). Alternately, a compound of the invention (70 mg) and asecondary agent (30 mg) are thoroughly blended with polyoxyethylenesorbitan monooleate (50 mg) and starch powder (250 mg), and theresulting mixture loaded into a gelatin capsule (400 mg of compositionper capsule).

Alternately, a compound of the invention (40 mg) is thoroughly blendedwith microcrystalline cellulose (Avicel PH 103; 259.2 mg) and magnesiumstearate (0.8 mg). The mixture is then loaded into a gelatin capsule(Size #1, White, Opaque) (300 mg of composition per capsule).

Exemplary Tablet Formulation for Oral Administration

A compound of the invention (10 mg), starch (45 mg) and microcrystallinecellulose (35 mg) are passed through a No. 20 mesh U.S. sieve and mixedthoroughly. The granules so produced are dried at 50-60° C. and passedthrough a No. 16 mesh U.S. sieve. A solution of polyvinylpyrrolidone (4mg as a 10% solution in sterile water) is mixed with sodiumcarboxymethyl starch (4.5 mg), magnesium stearate (0.5 mg), and talc (1mg), and this mixture is then passed through a No. 16 mesh U.S. sieve.The sodium carboxymethyl starch, magnesium stearate and talc are thenadded to the granules. After mixing, the mixture is compressed on atablet machine to afford a tablet weighing 100 mg.

Alternately, a compound of the invention (250 mg) is thoroughly blendedwith microcrystalline cellulose (400 mg), silicon dioxide fumed (10 mg),and stearic acid (5 mg). The mixture is then compressed to form tablets(665 mg of composition per tablet).

Alternately, a compound of the invention (400 mg) is thoroughly blendedwith cornstarch (50 mg), croscarmellose sodium (25 mg), lactose (120mg), and magnesium stearate (5 mg). The mixture is then compressed toform a single-scored tablet (600 mg of composition per tablet).

Alternately, a compound of the invention (100 mg) is thoroughly blendedwith cornstarch (100 mg) with an aqueous solution of gelatin (20 mg).The mixture is dried and ground to a fine powder. Microcrystallinecellulose (50 mg) and magnesium stearate (5 mg) are then admixed withthe gelatin formulation, granulated and the resulting mixture compressedto form tablets (100 mg of the compound of the invention per tablet).

Exemplary Suspension Formulation for Oral Administration

The following ingredients are mixed to form a suspension containing 100mg of the compound of the invention per 10 mL of suspension:

Ingredients Amount Compound of the invention 1.0 g Fumaric acid 0.5 gSodium chloride 2.0 g Methyl paraben 0.15 g Propyl paraben 0.05 gGranulated sugar 25.5 g Sorbitol (70% solution) 12.85 g Veegum ® K(magnesium aluminum silicate) 1.0 g Flavoring 0.035 mL Colorings 0.5 mgDistilled water q.s. to 100 mL

Exemplary Liquid Formulation for Oral Administration

A suitable liquid formulation is one with a carboxylic acid-based buffersuch as citrate, lactate and maleate buffer solutions. For example, acompound of the invention (which may be pre-mixed with DMSO) is blendedwith a 100 mM ammonium citrate buffer and the pH adjusted to pH 5, or isblended with a 100 mM citric acid solution and the pH adjusted to pH 2.Such solutions may also include a solubilizing excipient such as acyclodextrin, for example the solution may include 10 wt %hydroxypropyl-β-cyclodextrin.

Other suitable formulations include a 5% NaHCO₃ solution, with orwithout cyclodextrin.

Exemplary Injectable Formulation for Administration by Injection

A compound of the invention (0.2 g) is blended with 0.4 M sodium acetatebuffer solution (2.0 mL). The pH of the resulting solution is adjustedto pH 4 using 0.5 N aqueous hydrochloric acid or 0.5 N aqueous sodiumhydroxide, as necessary, and then sufficient water for injection isadded to provide a total volume of 20 mL. The mixture is then filteredthrough a sterile filter (0.22 micron) to provide a sterile solutionsuitable for administration by injection.

Exemplary Compositions for Administration by Inhalation

A compound of the invention (0.2 mg) is micronized and then blended withlactose (25 mg). This blended mixture is then loaded into a gelatininhalation cartridge. The contents of the cartridge are administeredusing a dry powder inhaler, for example.

Alternately, a micronized compound of the invention (10 g) is dispersedin a solution prepared by dissolving lecithin (0.2 g) in demineralizedwater (200 mL). The resulting suspension is spray dried and thenmicronized to form a micronized composition comprising particles havinga mean diameter less than about 1.5 m. The micronized composition isthen loaded into metered-dose inhaler cartridges containing pressurized1,1,1,2-tetrafluoroethane in an amount sufficient to provide about 10 μgto about 500 μg of the compound of the invention per dose whenadministered by the inhaler.

Alternately, a compound of the invention (25 mg) is dissolved in citratebuffered (pH 5) isotonic saline (125 mL). The mixture is stirred andsonicated until the compound is dissolved. The pH of the solution ischecked and adjusted, if necessary, to pH 5 by slowly adding aqueous 1 NNaOH. The solution is administered using a nebulizer device thatprovides about 10 μg to about 500 μg of the compound of the inventionper dose.

EXAMPLES

The following Preparations and Examples are provided to illustratespecific embodiments of the invention. These specific embodiments,however, are not intended to limit the scope of the invention in any wayunless specifically indicated.

The following abbreviations have the following meanings unless otherwiseindicated and any other abbreviations used herein and not defined havetheir standard, generally accepted meaning:

-   -   AcOH acetic acid    -   Bn benzyl    -   BOC t-butoxycarbonyl (—C(O)OC(CH₃)₃)    -   (BOC)₂O di-t-butyl dicarbonate    -   Cbz carbobenzyloxy (—C(O)O-benzyl)    -   DCC 1,3-dicyclohexylcarbodiimide    -   DCM dichloromethane or methylene chloride    -   DIPEA N,N-diisopropylethylamine    -   DMAP 4-dimethylaminopyridine    -   DMF N,N-dimethylformamide    -   DMSO dimethylsulfoxide    -   EDC 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide    -   EDTA ethylenediaminetetraacetic acid    -   Et₃N triethylamine    -   EtOAc ethyl acetate    -   EtOH ethanol    -   Et₂O diethyl ether    -   HATU N,N,N′,N′-tetramethyl-O-(7-azabenzotriazol-1-yl)uronium        hexafluorophosphate    -   HOBt 1-hydroxybenzotriazole    -   HMPA Hexamethylphosphoramide    -   LDA Lithium diisopropylamide    -   LiHMDS lithium hexamethyl disilazide    -   MeCN acetonitrile    -   MeOH methanol    -   MTBE methyl t-butyl ether    -   NaHMDS sodium bis(trimethylsilyl)amide    -   Pd(dppf)₂Cl₂ 1,1-bis(diphenylphosphino)ferrocene palladium        chloride    -   PdOH₂/C palladium hydroxide on carbon (Pearlman's catalyst)    -   Pd(PPh₃)₄ tetrakis(triphenylphosphine)palladium(0)    -   PPh₃ Triphenylphosphine    -   PE petroleum ether    -   TFA trifluoroacetic acid    -   THF tetrahydrofuran

Unless noted otherwise, all materials, such as reagents, startingmaterials and solvents, were purchased from commercial suppliers (suchas Sigma-Aldrich, Fluka Riedel-de Haën, and the like) and were usedwithout further purification.

Reactions were run under nitrogen atmosphere, unless noted otherwise.The progress of reactions were monitored by thin layer chromatography(TLC), analytical high performance liquid chromatography (anal. HPLC),and mass spectrometry, the details of which are given in specificexamples. Solvents used in analytical HPLC were as follows: solvent Awas 98% H₂O/2% MeCN/1.0 mL/L TFA; solvent B was 90% MeCN/10% H₂O/1.0mL/L TFA.

Reactions were worked up as described specifically in each preparationfor example; commonly reaction mixtures were purified by extraction andother purification methods such as temperature-, and solvent-dependentcrystallization, and precipitation. In addition, reaction mixtures wereroutinely purified by preparative HPLC, typically using Microsorb C18and Microsorb BDS column packings and conventional eluents. Progress ofreactions was typically measured by liquid chromatography massspectrometry (LCMS). Characterization of isomers were done by NuclearOverhauser effect spectroscopy (NOE). Characterization of reactionproducts was routinely carried out by mass and ¹H-NMR spectrometry. ForNMR measurement, samples were dissolved in deuterated solvent (CD₃OD,CDCl₃, or DMSO-d₆), and ¹H-NMR spectra were acquired with a VarianGemini 2000 instrument (400 MHz) under standard observation conditions.Mass spectrometric identification of compounds was typically conductedusing an electrospray ionization method (ESMS) with an AppliedBiosystems (Foster City, Calif.) model API 150 EX instrument or anAgilent (Palo Alto, Calif.) model 1200 LC/MSD instrument.

It is understood that many of the compounds described in thePreparations and Examples can exist in a tautomer form, and that bothforms are intended to be covered. For example,(2S,4S)-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-methoxymethyl-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicacid is depicted in Example 2-1 but it is understood that this compoundcan exist in a tautomer form, for example, as(2S,4S)-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-methoxymethyl-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicacid.

Preparation 1:(2S,4S)-5-(4-Bromophenyl)-4-t-butoxycarbonylamino-2-hydroxymethylpentanoicAcid Ethyl Ester

A mixture of (S)-2-(4-bromobenzyl)-5-oxopyrrolidine-1-carboxylic acidt-butyl ester (52 g, 147 mmol) andt-butoxy-N,N,N′,N′-tetramethylmethanediamine (50 g, 286 mmol) wasstirred at 80° C. for 4 hours under argon. The mixture was diluted withEtOAc (500 mL) and washed with water (300 mL) and saturated aqueous NaCl(300 mL), dried over NaSO₄, and concentrated to yield Compound 1 (60 g)as a red oil. LC-MS: [M+H]+: 410.

To a solution of Compound 1 (60 g, 147 mmol) in THF (600 mL) was added 1M HCl (175 mL, 175 mmol) at 0° C. under nitrogen. After stirring for 1hour at room temperature, the mixture was diluted with EtOAc (500 mL)and adjusted with saturated aqueous NaHCO₃ to pH 7. The aqueous layerwas extracted with EtOAc (2×300 mL) and the combined organic layers werewashed with water (2×500 mL) and saturated aqueous NaCl (500 mL), driedover NaSO₄, and concentrated to yield Compound 2 (56 g) as a yellowsolid. LC-MS: [2M+Na]+: 787

To a solution of Compound 2 (20 g, 52 mmol) in MeOH (600 mL) was added1M HCl (210 mL, 210 mmol) at 0° C. under nitrogen. The mixture wasstirred at 0° C. for 1 hour, then NaBH₃CN (13.2 g, 210 mmol) was addedin small portions over 30 minutes. After stirring for 2 hours at 0° C.,the mixture was adjusted with saturated aqueous NaHCO₃ to pH 7 andconcentrated. The aqueous layers were extracted with EtOAc (3×200 mL)and the combined organic layers were washed with water (2×100 mL) andsaturated aqueous NaCl (100 mL), dried over Na₂SO₄, filtered, andconcentrated to yield the crude residue, which was further purified bysilica gel chromatography (PE:EtOAc=5:1) to yield Compound 3 (10 g) as awhite solid. LC-MS: [2M+Na]+: 791

To a solution of Compound 3 (10 g, 26 mmol) in anhydrous EtOH (800 mL)was added anhydrous K₂CO₃ (14.3 g, 104 mmol) at 0° C. under nitrogen.After stirring for 1 hour at 0° C., the mixture was warmed to roomtemperature and stirred for 16 hours. After filtration, the filtrate wasconcentrated and the reside was purified by silica gel chromatography(PE:EtOAc=5:1 to 2:1) to yield the title compound (2.5 g) as a colorlessoil. LC-MS: [M+Na]+: 453

Preparation 2:(2S,4S)-4-t-Butoxycarbonylamino-5-(5′-chloro-2′-fluoro-biphenyl-4-yl)-2-hydroxymethylpentanoicAcid Ethyl Ester

(2S,4S)-5-(4-Bromophenyl)-4-t-butoxycarbonylamino-2-hydroxymethylpentanoicacid ethyl ester (6 g, 13.9 mmol), 5-chloro-2-fluorophenylboronic acid(2.7 g, 15.3 mmol), Pd(dppf)Cl₂ (500 mg, 683 μmol), and KF (1.6 g, 27.8mmol) in dioxane (50 mL) and water (50 mL) were combined in a flask thathad been evacuated and back-filled with nitrogen. The mixture wasstirred at 80° C. for 4 hours, then extracted with EtOAc (2×50 mL), andthe organic layers were concentrated and purified by silica gelchromatography (PE:EtOAc=5:1) to yield the title compound (4 g) as ayellow oil. LC-MS: [2M+Na]⁺: 982; ¹H NMR (300 MHz, CDCl₃): δ ppm7.05˜7.44 (m, 7H), 4.4 (s, 1H), 4.1˜4.2 (m, 2H), 3.85 (s, 1H), 3.76 (m,2H), 2.7˜2.85 (m, 3H), 1.94˜2.02 (m, 2H), 1.59 (s, 1H), 1.40 (s, 9H),1.24˜1.29 (t, 3H); ¹³C NMR (75 MHz, CDCl₃): δ ppm 174.65, 159.98,156.71, 155.50, 138.16, 129.87, 129.04, 128.61, 117.78, 117.45, 79.63,63.77, 61.16, 50.34, 44.91, 41.73, 33.30, 28.70, 14.54.

Preparation 3:(2S,4S)-4-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-methoxymethylpentanoicAcid Ethyl Ester

(2S,4S)-4-t-Butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-hydroxymethylpentanoicacid ethyl ester (1.5 g, 3.1 mmol) was combined with 10N NaOH (2.2 mL,21.9 mmol), DCM (12 mL), and tetrabutylammonium hydrogen sulfate (212mg, 625 μmol). Dimethyl sulfate (512 mg, 4.1 mmol) was added, thereaction flask was capped and stirred vigorously overnight. The DCMlayer was extracted and concentrated under reduced pressure. The residuewas purified by normal phase chromatography (0-80% EtOAc/hexanes) toyield Compound 1 (630 mg).

Compound 1 (292 mg, 591 μmol) was dissolved in MeCN (2 mL) and 4N HCl indioxane (0.6 mL) and stirred for 10 minutes. The mixture wasconcentrated under reduced pressure to yield the title compound as anHCl salt, which was used without further purification.

Preparation 4:(2S,4S)-4-t-Butoxycarbonylamino-5-(3′-chlorobiphenyl-4-yl)-2-hydroxymethylpentanoicAcid Ethyl Ester

(2S,4S)-5-(4-Bromophenyl)-4-t-butoxycarbonylamino-2-hydroxymethylpentanoicacid ethyl ester (5.5 g, 12.8 mmol), 3-chlorophenylboronic acid (2.2 g,14 mmol), Pd(dppf)Cl₂ (500 mg, 683 μmol), and KF (1.5 g, 25.6 mmol) indioxane (50 mL) and water (50 mL) were combined in a flask that had beenevacuated and back-filled with nitrogen. The mixture was stirred at 80°C. for 4 hours, then extracted with EtOAc (2×50 mL), and the organiclayers were concentrated and purified by silica gel chromatography(PE:EtOAc=5:1) to yield the title compound (3.3 g) as a yellow oil.LC-MS: [2M+Na]⁺: 947; 1H NMR (300 MHz, CDCl₃): δ ppm 7.23˜7.54 (m, 8H),4.4 (s, 1H), 4.1˜4.2 (m, 2H), 3.85 (s, 1H), 3.7 (m, 2H), 2.69˜2.85 (m,3H), 1.93˜2.09 (m, 2H), 1.59 (s, 1H), 1.40 (s, 9H), 1.24˜1.29 (t, 3H).

Preparation 5:(2S,4S)-4-Amino-5-(3′-chlorobiphenyl-4-yl)-2-methoxymethylpentanoic AcidEthyl Ester

(2S,4S)-4-t-Butoxycarbonylamino-5-(3′-chlorobiphenyl-4-yl)-2-hydroxymethylpentanoicacid ethyl ester (1.4 g, 3.1 mmol) was combined with 10N NaOH (2.2 mL,21.9 mmol), DCM (12 mL), and tetrabutylammonium hydrogen sulfate (212mg, 625 μmol). Dimethyl sulfate (512 mg, 4.1 mmol) was added, thereaction flask was capped and stirred vigorously overnight. The DCMlayer was extracted and concentrated under reduced pressure. The residuewas purified by normal phase chromatography (0-80% EtOAc/hexanes) toyield Compound 1 (650 mg).

Compound 1 (281 mg, 591 μmol) was dissolved in MeCN (2 mL) and 4N HCl indioxane (0.6 mL) and stirred for 10 minutes. The mixture wasconcentrated under reduced pressure to yield the title compound as anHCl salt, which was used without further 5 purification.

Preparation 6:(2S,4S)-5-Biphenyl-4-yl-4-t-butoxycarbonylamino-2-hydroxymethylpentanoicAcid Ethyl Ester

To a solution of (R)-3-biphenyl-4-yl-2-t-butoxycarbonylamino-propionicacid (50 g, 146 mmol), Meldrum's acid (23.3 g, 161 mmol) and DMAP (27.8g, 227 mmol) in anhydrous DCM (500 mL) was added a solution of DCC (33.3g, 161 mmol) in anhydrous DCM (200 mL) over 1 hour at −5° C. undernitrogen. The mixture was stirred at −5° C. for 8 hours, thenrefrigerated overnight, during which time, tiny crystals ofdicyclohexylurea precipitated. After filtration, the mixture was washedwith 5% KHSO₄ (4×200 mL) and saturated aqueous NaCl (200 mL), then driedunder refrigeration with MgSO₄ overnight. The solution was filtered andevaporated to yield Compound 1 (68 g) as a light yellow solid, which wasused without further purification. LC-MS: 490 [M+Na], 957 [2M+Na].

To a solution of crude Compound 1 (68 g, 147 mmol) in anhydrous DCM (1L) was added AcOH (96.7 g, 1.6 mol) at −5° C. under nitrogen. Themixture was stirred at −5° C. for 0.5 hour, then NaBH₄ (13.9 g, 366mmol) was added in small portions over 1 hour. After stirring for anadditional one hour at −5° C., saturated aqueous NaCl (300 mL) wasadded. The organic layer was washed with saturated aqueous NaCl (2×300mL) and water (2×300 mL), dried over MgSO₄, filtered, and evaporated toyield the crude residue, which was further purified by chromatography(hexanes:EtOAc=5:1) to yield Compound 2 (46 g) as a light yellow solid.LC-MS: 476 [M+Na], 929 [2M+Na].

A solution of Compound 2 (46 g, 101 mmol) in anhydrous toluene (300 mL)was refluxed under nitrogen for 3 hours. After evaporation of thesolvent, the residue was purified by chromatography (hexanes:EtOAc=10:1)to yield Compound 3 (27 g) as a light yellow solid. LC-MS: 374 [M+Na],725 [2M+Na]. ¹H NMR (300 MHz, CDCl₃): δ7.64-7.62 (m, 4H), 7.51-7.46 (m,2H), 7.42-7.39 (m, 1H), 7.39-7.30 (m, 2H), 4.50-4.43 (m, 1H), 3.27-3.89(m, 1H), 2.88-2.80 (m, 1H), 2.48-2.42 (m, 2H), 2.09-1.88 (m, 2H), 1.66(s, 9H).

A mixture of Compound 3 (27 g, 77 mmol) andt-butoxy-N,N,N′,N′-tetramethylmethanediamine (40.3 g, 231 mmol) washeated to 80° C. under nitrogen. After stirring for 3 hours at 80° C.,the mixture was diluted with EtOAc (300 mL), washed with water (2×150mL) and saturated aqueous NaCl (2×150 mL), dried over MgSO₄, filtered,and evaporated to yield crude Compound 4 (29.7 g, light yellow oil).LC-MS: 425 [M+H], 835 [2M+H].

To a solution of crude Compound 4 (29.7 g, 73 mmol) in THF (200 mL) wasadded 1 M HCl (81 mL) at 0° C. under nitrogen. After stirring for 1 hourat room temperature, the mixture was diluted with EtOAc (100 mL) andadjusted with saturated aqueous NaHCO₃ to pH 7. The aqueous layer wasextracted with EtOAc (2×150 mL) and the combined organic layers werewashed with water (2×150 mL) and saturated aqueous NaCl (150 mL), driedover MgSO₄, filtered, and evaporated to yield crude Compound 5 (29.4 g,yellow oil). LC-MS: 402 [M+Na], 781 [2M+Na].

To a solution of Compound 5 (29.4 g, 77 mmol) in anhydrous THF (300 mL)was added anhydrous EtOH (30 mL) and AcOH (92.5 g, 1.5 mol) at −5° C.under nitrogen. The mixture was stirred at −5° C. for 0.5 hour, thenNaBH₃CN (19.4 g, 308 mmol) was added in small portions over 1 hour.After stirring for one additional hour at −5° C., the mixture wasadjusted with saturated aqueous NaHCO₃ to pH 7. The aqueous layers wereextracted with EtOAc (2×200 mL) and the combined organic layers werewashed with water (2×150 mL) and saturated aqueous NaCl (150 mL), driedover MgSO₄, filtered, and concentrated to yield the crude residue, whichwas further purified by chromatography (hexanes:EtOAc=5:1) to yieldCompound 6 (11.2 g) as a light yellow solid. LC-MS: 404 [M+Na], 785[2M+Na].

To a solution of Compound 6 (11.2 g, 29 mmol) in anhydrous EtOH (500 mL)was added anhydrous K₂CO₃ (8.0 g, 58 mmol) at 0° C. under nitrogen.After stirring for 1 hour at 0° C., the mixture was warmed to roomtemperature and stirred for 16 hours. After filtration, the filtrate wasconcentrated and the residue was diluted with water (150 mL), DCM (200mL) and saturated aqueous NaCl (50 mL). After separation, the aqueouslayer was extracted with DCM (2×150 mL). The combined organic layerswere washed with saturated aqueous NaCl (2×200 mL), dried over MgSO₄,and concentrated to yield the crude residue which was further purifiedby column chromatography (hexanes:EtOAc=5:1) to yield the (S,S) titlecompound (8.3 g) as a light yellow solid, as well as the (R,S) isomer.

(S,S) title compound: LC-MS: 450 [M+Na], 877 [2M+Na]. ¹H NMR (300 MHz,CDCl₃): δ7.58-7.23 (m, 9H), 4.46-4.43 (d, 1H), 4.20-4.13 (m, 2H), 3.94(s, 1H), 3.82-3.70 (m, 2H), 2.85-2.70 (m, 3H), 2.25-2.22 (d, 1H),2.01-1.92 (m, 1H), 1.47 (s, 9H), 1.26-1.24 (m, 3H).

(R,S) isomer: LC-MS: 450 [M+Na], 877 [2M+Na]. ¹H NMR (300 MHz, CDCl₃):δ7.58-7.55 (m, 4H), 7.50-7.43 (m, 2H), 7.40-7.30 (m, 1H), 7.26-7.23 (m,1H), 4.46 (m, 1H), 4.21-4.13 (m, 2H), 3.94 (m, 1H), 3.82-3.77 (m, 2H),2.83-2.81 (d, 2H), 2.66-2.63 (m, 1H), 2.24 (m, 1H), 1.83-1.81 (m, 2H),1.38 (s, 9H), 1.30-1.25 (m, 3H).

Preparation 7: (2S,4S)-4-Amino-5-biphenyl-4-yl-2-methoxymethylpentanoicAcid Ethyl Ester

(2S,4S)-5-Biphenyl-4-yl-4-t-butoxycarbonylamino-2-hydroxymethylpentanoicacid ethyl ester (69 mg, 140 μmol) was combined with DCM (1 mL), 10NNaOH (98 μL, 982 μmol), tetrabutylammonium hydrogen sulfate (9.5 mg, 28μmol) and dimethyl sulfate (54 μL, 561 μmol). The mixture was stirredovernight and the DCM layer was purified by normal phase chromatography(0-100% EtOAc/hexanes) to yield Compound 1 (30 mg).

Compound 1 (21.7 mg, 49 μmol) was dissolved in MeCN (0.3 mL) and 4Ndioxane (0.3 mL) and stirred for 10 minutes. The mixture wasconcentrated under reduced pressure to yield the title compound as anHCl salt.

Preparation 8:(2S,4S)-4-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-ethoxymethylpentanoicAcid Ethyl Ester

(2S,4S)-4-t-Butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-hydroxymethylpentanoicacid ethyl ester (1.5 g, 3.1 mmol) was combined with 10N NaOH (2.2 mL,21.9 mmol), DCM (12 mL), and tetrabutylammonium hydrogen sulfate (212mg, 625 μmol). Diethyl sulfate (626 mg, 4.1 mmol) was added, thereaction flask was capped and stirred vigorously overnight. The DCMlayer was extracted and concentrated under reduced pressure. The residuewas purified by normal phase chromatography (0-80% EtOAc/hexanes) toyield Compound 1 (300 mg).

Compound 1 (300 mg, 591 μmol) was dissolved in MeCN (2 mL) and 4N HCl indioxane (0.6 mL) and stirred for 10 minutes. The mixture wasconcentrated under reduced pressure to yield the title compound as anHCl salt, which was used without further purification.

Preparation 9:(2S,4S)-4-Amino-5-(3′-chlorobiphenyl-4-yl)-2-ethoxymethylpentanoic AcidEthyl Ester

(2S,4S)-4-t-Butoxycarbonylamino-5-(3′-chlorobiphenyl-4-yl)-2-hydroxymethylpentanoicacid ethyl ester (1.4 g, 3.1 mmol) was combined with 10N NaOH (2.2 mL,21.9 mmol), DCM (12 mL), and tetrabutylammonium hydrogen sulfate (212mg, 625 μmol). Diethyl sulfate (626 mg, 4.1 mmol) was added, thereaction flask was capped and stirred vigorously overnight. The DCMlayer was extracted and concentrated under reduced pressure. The residuewas purified by normal phase chromatography (0-80% EtOAc/hexanes) toyield Compound 1 (350 mg).

Compound 1 (289 mg, 591 μmol) was dissolved in MeCN (2 mL) and 4N HCl indioxane (0.6 mL) and stirred for 10 minutes. The mixture wasconcentrated under reduced pressure to yield the title compound, whichwas used without further purification.

Preparation 10: (2S,4S)-4-Amino-5-biphenyl-4-yl-2-ethoxymethylpentanoicAcid Ethyl Ester

(2S,4S)-5-Biphenyl-4-yl-4-t-butoxycarbonylamino-2-hydroxymethylpentanoicacid ethyl ester (60 mg, 140 μmol) was combined with 10N NaOH (98 μL,982 μmol), DCM (1 mL), tetrabutylammonium hydrogen sulfate (9.5 mg, 28μmol), and diethyl sulfate (87 mg, 561 μmol). The mixture was stirredovernight and the DCM layer was purified by normal phase chromatography(0-100% EtOAc/hexanes) to yield Compound 1 (15 mg).

Compound 1 (22.4 mg, 49 μmol) was dissolved in MeCN (0.3 mL) and 4N HClin dioxane (0.3 mL) and stirred for 10 minutes. The mixture wasconcentrated under reduced pressure to yield the title compound as anHCl salt, which was used without further purification.

Preparation 11:(2S,4S)-4-Amino-5-biphenyl-4-yl-2-(2-hydroxyethoxymethyl)pentanoic AcidEthyl Ester

(2S,4S)-5-Biphenyl-4-yl-4-t-butoxycarbonylamino-2-hydroxymethylpentanoicacid 5 ethyl ester (60 mg, 140 μmol) was combined with 10N NaOH (98 μL,982 μmol), DCM (1 mL), tetrabutylammonium hydrogen sulfate (9.5 mg, 28μmol), and [1,3,2]dioxathiolane 2,2-dioxide (70 mg, 561 μmol). Themixture was stirred overnight and the DCM layer was separated, driedover Na₂SO₄, and purified by normal phase chromatography (0-100%EtOAc/hexanes) to yield Compound 1 (8 mg).

Compound 1 (23.2 mg, 49 μmol) was dissolved in MeCN (0.3 mL) and 4N HClin dioxane (0.3 mL) and stirred for 10 minutes. The mixture wasconcentrated under reduced pressure to yield the title compound as anHCl salt, which was used without further purification.

Preparation 12:(2S,4S)-4-Amino-5-biphenyl-4-yl-2-(3-hydroxypropoxymethyl)pentanoic AcidEthyl Ester

(2S,4S)-5-Biphenyl-4-yl-4-t-butoxycarbonylamino-2-hydroxymethylpentanoicacid ethyl ester (60 mg, 140 μmol) was combined with 10N NaOH (98 μL,982 μmol), DCM (1 mL), tetrabutylammonium hydrogen sulfate (9.5 mg, 28μmol), and [1,3,2]dioxathiane 2,2-dioxide (78 mg, 561 μmol). The mixturewas stirred overnight and the DCM layer was separated, dried overNa₂SO₄, and purified by normal phase chromatography (0-100%EtOAc/hexanes) to yield Compound 1 (9 mg).

Compound 1 (23.9 mg, 49 μmol) was dissolved in MeCN (0.3 mL) and 4N HClin dioxane (0.3 mL) and stirred for 10 minutes. The mixture wasconcentrated under reduced pressure to yield the title compound as anHCl salt, which was used without further purification.

Preparation 13:(2R,4R)-4-t-Butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-hydroxypentanoicAcid Ethyl Ester

To a solution of (S)-2-(4-bromobenzyl)-5-oxopyrrolidine-1-carboxylicacid t-butyl ester (25 g, 70.6 mmol) in 1,4-dioxane (500 mL) was added5-chloro-2-fluorophenylboronic acid (24.6 g, 141 mmol), Pd(PPh₃)₄ (4.1g, 3.5 mmol) and a solution of K₂CO₃ (17.8 g, 141 mmol) in water (90mL), at room temperature under nitrogen. The mixture was heated to 60°C. and stirred overnight. Water (500 mL) was added and the solventevaporated. The mixture was extracted with EtOAc (3×200 mL). Thecombined organic layers were washed with saturated aqueous NaCl (300 mL)and filtered. The filtrate was concentrated to yield the crude residuewhich was purified by chromatography to yield Compound 1 (22.7 g) as alight yellow solid. LC-MS: 829.2 [2M+Na⁺].

To a solution of Compound 1 (4.9 g, 12.1 mol) in DCM (100 mL) was addedTFA (4.5 mL, 60.7 mmol) at 0° C. under nitrogen, and stirred for 1 hour.The mixture was warmed to room temperature for 1.5 hours. Afterevaporation of the solvent, the residue was diluted with EtOAc (100 mL),then washed with saturated aqueous NaHCO₃ (3×100 mL), water (2×100 mL),saturated aqueous NaCl (100 mL), then dried over Na₂SO₄. The mixture wasfiltered and the filtrate was concentrated to yield crude Compound 2.LC-MS: 304 [M+H]⁺.

To a solution of NaH (2.4 g, 695 mmol) in THF (200 mL) was addeddropwise a solution of Compound 2 (8.5 g, 278 mmol) in THF (50 mL) at 0°C. under nitrogen. The mixture was warmed to room temperature andstirred for 2 hours. After cooling to 0° C., pivaloyl chloride (5 g,41.7 mmol) was added dropwise over 30 minutes. The mixture was warmed toroom temperature and stirred for 9.5 hours. The reaction was quenchedwith saturated aqueous NH₄Cl (250 mL) and extracted with EtOAc (3×400mL). The combined organic layers were dried over Na₂SO₄ and concentratedto yield the crude residue which was purified by chromatography to yieldCompound 3 (18 g) as a yellow solid. LC-MS: 388 [M+H⁺].

To a solution of Compound 3 (9 g, 23.2 mmol) in THF (200 mL) was addeddropwise NaHMDS (20.9 mL, 41.8 mmol) at −78° C. under nitrogen. Afterstirring for 1 hour at −78° C., a solution of(+)-(8,8-dichlorocamphorylsulfonyl)oxaziridine (10.4 g, 34.8 mmol) inTHF (50 mL) was added dropwise. After stirring at −78° C. for 1 hour,the reaction was quenched with saturated aqueous NH₄Cl (50 mL) andextracted with EtOAc (3×400 mL). The combined organic layers were washedwith 1M HCl (400 mL), saturated aqueous NaHCO₃ (400 mL), and saturatedaqueous NaCl (400 mL), dried over Na₂SO₄, and concentrated to give thecrude residue which was purified by chromatography to yield Compound 4(8.8 g) as a white semi-solid. LC-MS: 426.1 [M+Na⁺].

A solution of Compound 4 (8.8 g, 21.8 mmol) in EtOH (12 mL) was added toconcentrated HCl (200 mL) and heated at 100° C. and stirred overnight.The mixture was then concentrated to give the crude residue which waspurified by washing with Et₂O (100 mL) to yield Compound 5 (7.5 g) as asolid HCl salt. LC-MS: 338 [M+H⁺].

A solution of Compound 5 (7.5 g, 20.1 mmol) in EtOH/HCl (100 mL) washeated at 50° C. overnight. The mixture was concentrated and the cruderesidue was purified by washing with Et₂O (200 mL) to yield Compound 6(6.5 g) as a white solid HCl salt. LC-MS: 366.1 [M+H⁺].

Compound 6 (2 g, 5.5 mmol) and di-t-butyl dicarbonate (1.5 mL, 6.6 mmol)were mixed in DCM (10 mL) followed by DIPEA (1.9 mL, 10.9 mmol). Themixture was stirred at room temperature for 3 hours, at which time LCMSindicated the mass of the desired compound. The solvent was removed andthe residue was purified by normal phase column chromatography (20-100%EtOAc/hexanes) to yield the title compound (2.5 g).

Preparation 14:(2R,4R)-4-Amino-2-azido-5-(5′-chloro-2′-fluorobiphenyl-4-yl)pentanoicAcid Ethyl Ester

(2R,4R)-4-t-Butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-hydroxy-pentanoicacid ethyl ester (2.5 g, 5.4 mmol) was dissolved in DCM (10 mL).Methanesulfonyl chloride (460 μL, 6.0 mmol) was added, followed by Et₃N(1.5 mL, 10.8 mmol). The mixture was stirred at room temperature for 10minutes, at which time LCMS indicated the mass of the desired compound.EtOAc and a saturated aqueous NH₄Cl were added. The organic layer wasextracted, separated, dried over MgSO₄, filtered, and evaporated toyield crude Compound 1, which was used directly in the next step.

Compound 1 (2.9 g, 5.4 mmol) in DMF (6 mL) was combined with sodiumazide (422 mg, 6.5 mmol), and the resulting mixture was stirred at 50°C. for 4 hours, at which time LCMS indicated the mass of the desiredcompound. EtOAc and water were added. The organic layer was extracted,separated and dried over MgSO₄, filtered, and evaporated. The residuewas purified by normal phase column chromatography (20-100%EtOAc/hexanes) to yield Compound 2 (2.1 g) as a yellow oil.

Compound 2 (2.1 g, 4.2 mmol) was dissolved in MeCN (6 mL). A solution of4N HCl in dioxane (10.5 mL, 42.2 mmol) was added, and the mixture wasstirred at room temperature for 20 minutes then concentrated in vacuo toyield the crude title compound as an HCl salt, which was used withoutfurther purification.

Preparation 15:(2R,4R)-4-Amino-5-(4-bromo-2-chlorophenyl)-2-hydroxypentanoic Acid EthylEster

To a suspension of 4-bromo-2-chlorobenzaldehyde (50 g, 22.8 mmol) inMeOH (500 mL) was added NaBH₄ (17.3 g, 45.6 mmol) in portions at 0° C.The mixture was stirred for 30 minutes and then aqueous NH₄Cl was addedto quench the reaction. The mixture was concentrated in vacuo. Theresidue was extracted with EtOAc (200 mL×2) and the combined organiclayers were dried over Na₂SO₄, and concentrated in vacuo to yieldCompound 1 (48 g) as a white solid.

To a solution of Compound 1 (46.8 g, 21.1 mmol) in dry DCM (500 mL) wasadded phosphorous tribromide (68.6 g, 25.3 mmol) dropwise at 0° C. undernitrogen. The mixture was stirred for 2 hours and then washed withsaturated aqueous NaHCO₃ (200 mL×2) and saturated aqueous NaCl (200 mL),dried over Na₂SO₄, concentrated in vacuo to yield Compound 2 (36 g) as acolorless oil.

To a stirred solution of (R)-pyrrolidine-2-carboxylic acid (57.7 g, 0.5mol) and KOH (84 g, 1.5 mol) in isopropyl alcohol (330 mL) was addedbenzyl chloride (70 mL, 0.6 mol) dropwise at 0° C. over 3 hours. Themixture was then stirred overnight at the same temperature. Theresulting mixture was neutralized with concentrated HCl to pH 6,followed by the addition of chloroform (200 mL). The mixture was stirredfor 30 minutes, then filtered and the precipitate was washed withchloroform (100 mL×3). The combined chloroform solutions were dried overNa₂SO₄, and concentrated in vacuo to yield Compound 3 (52 g) as a whitesolid. LC-MS: 206 [M+H]⁺.

To a solution of Compound 3 (10 g, 48.8 mmol) in dry DCM (50 mL) wasadded SO₂Cl₂ (7.3 g, 61 mmol) at −20° C. under nitrogen. The mixture wasstirred at −20° C. for 3 hours followed by the addition of a solution of(2-aminophenyl)(phenyl)methanone (6 g, 30.5 mmol) in dry DCM (25 mL) andthe mixture was stirred overnight at room temperature. A solution ofNa₂CO₃ (10.3 g) in water (40 mL) was added at 0° C. The organic layerwas separated and the aqueous layer was extracted with DCM (50 mL×3).The combined organic layers were dried over Na₂SO₄ and concentrated invacuo. The residue was washed with MTBE (50 mL×2) to yield Compound 4(8.5 g) as a yellow solid. LC-MS: 385 [M+H]⁺.

To a solution of Compound 4 (29.4 g, 76.5 mmol), glycine (28.7 g, 382.4mmol) and Ni(NO₃)₂.6H₂O (44.5 g, 152.9 mmol) in MeOH (280 mL) was addeda solution of KOH (30 g, 535.3 mmol) in MeOH (100 mL) at 45° C. undernitrogen. The mixture was stirred at 60° C. for an hour. The resultingsolution was neutralized with AcOH (31 mL) and poured into ice water(380 mL). The resulting solid was filtered and dissolved in DCM (450mL), which was washed with saturated aqueous NaCl (150 mL), dried overNa₂SO₄ and concentrated. The residue was washed with EtOAc (50 mL×2) toyield compound 5 (38 g) as a red solid. LC-MS: 498 [M+H]⁺.

Compound 5 (14.3 g, 28.7 mmol) and NaOH (3.4 g, 81.6 mmol) were added toa flask which was purged with nitrogen twice. Anhydrous DMF (100 mL) wasadded and the mixture was stirred for 5 minutes at 0° C. before asolution of Compound 2 (8.6 g, 30.1 mmol) in DMF (20 mL) was added. Thereaction mixture was stirred at room temperature for 30 minutes untilcomplete consumption of Compound 4 (checked by TLC). The resultingmixture was poured into a 5% AcOH aqueous solution (120 mL) which wasthen extracted with DCM (150 mL×3) and the combined organic layers werewashed with saturated aqueous NaCl (150 mL), dried over Na₂SO₄ andconcentrated in vacuo. The residue was recrystallized with DCM/Et₂O(1:1) to yield Compound 6 (15.5 g) as a red solid. LC-MS: 702 [M+H]⁺.

To a solution of Compound 6 (46 g, 65.6 mmol) in MeOH (300 mL) was added3N HCl (200 mL). The mixture was refluxed until the red color turnedgreen. The resulting solution was concentrated in vacuo beforeconcentrated NH₃.H₂O (100 mL) was added. The solution was extracted withDCM (200 mL×2) and the aqueous phase was concentrated in vacuo andsubjected to the cation exchange resin (eluted with NH₃.H₂O/EtOH, 1:1)to yield Compound 7 (15 g) as a white solid. LC-MS: 280 [M+H]⁺.

To a suspension of Compound 7 (15 g, 53.9 mmol) in MeCN (150 mL) wasadded a solution of NaOH (4.3 g, 107.7 mmol) in water (150 mL) at 0° C.,followed by the addition of (BOC)₂O (17.6 g, 80.8 mmol). The mixture wasstirred overnight at room temperature. The resulting solution wasconcentrated in vacuo, followed by extraction with DCM (150 mL×2). Thelayers were separated and the aqueous phase was acidified with 1N HCl topH 3 and extracted with EtOAc (150 mL×3). The combined organic layerswere washed with saturated aqueous NaCl (150 mL), dried over Na₂SO₄,filtered and concentrated in vacuo to yield Compound 8 (12.3 g, 60%) asa white solid. LC-MS: 402 [M+Na]⁺.

To a suspension of Compound 8 (18.4 g, 48.5 mmol) and Meldrum's acid(8.4 g, 58.2 mmol) in DCM (400 mL) was added DMAP (9.5 g, 77.6 mmol) at−5° C. After stirring for 10 minutes, a solution of DCC (12 g, 58.2mmol) in DCM (100 mL) was added dropwise at −5° C. The mixture wasstirred overnight at room temperature. The resulting solution was cooledto 0° C. and filtered. The filtrate was washed with aqueous citric acid(200 mL×3) and saturated aqueous NaCl (200 mL), dried over Na₂SO₄,filtered, and concentrated in vacuo. The residue was triturated withEt₂O (50 mL×2) to yield Compound 9 (22 g) as a light yellow solid.

To a solution of Compound 9 (22 g, 43.6 mmol) in DCM (400 mL) was addedAcOH (28.8 g, 479.4 mmol) at 0° C. After stirring for 10 minutes, NaBH₄(4.1 g, 109 mmol) was added in portions. The mixture was stirred for anhour at 0° C. The resulting solution was washed with saturated aqueousNaHCO₃ (200 mL×2) and saturated aqueous NaCl (200 mL), dried over Na₂SO₄and concentrated in vacuo. The residue was washed with ether (100 mL×2)to yield Compound 10 (18.6 g) as an off-white solid. LC-MS: 514 [M+Na]⁺.

A solution of Compound 10 (18.6 g, 37.9 mmol) in toluene (350 mL) washeated under reflux for 2 hours. Upon cooling, the mixture wasevaporated to dryness to yield Compound 11 (14 g) as a yellow syrup.LC-MS: 334 [M-tBu+H]⁺.

To a solution of Compound 11 (14 g, 36.0 mmol) in DCM (250 mL) was addedTFA (20 mL). The mixture was stirred for 4 hours at 0° C. The resultingsolution was concentrated in vacuo to remove TFA. The residue wasdissolved in DCM (400 mL) and washed with saturated aqueous NaHCO₃ (200mL×2), dried over Na₂SO₄ and concentrated to yield Compound 12 (10 g) asa yellow solid. LC-MS: 290 [M+H]⁺.

To a solution of Compound 12 (10 g, 34.7 mmol) in dry THF (250 mL) wasadded NaH (2.4 g, 69.3 mmol, 70%) at 0° C. The mixture was stirred forone hour at 0° C. under nitrogen, then pivaloyl chloride (5 g, 41.6mmol) was added. After stirring for another 2 hours, saturated aqueousNaHCO₃ (100 mL) was added to quench the reaction. The resulting mixturewas concentrated and extracted with EtOAc (100 mL×3) and the combinedorganic layers were washed with saturated aqueous NaCl (100 mL), driedover Na₂SO₄ and concentrated in vacuo. The residue was purified bysilica gel chromatography (hexanes/EtOAc, 5:1) to yield Compound 13(11.8 g) as a white solid. LC-MS: 374[M+H]⁺.

To a solution of Compound 13 (11.8 g, 31.8 mmol) in dry THF (70 mL) wasadded NaHMDS (24 mL, 47.7 mmol, 2.0 M in THF) dropwise at −78° C. undernitrogen. After stirring for 30 minutes, a solution of(+)-(8,8-dichlorocamphorylsulfonyl)-oxaziridine (15.2 g, 50.8 mmol) inTHF (70 mL) was added dropwise at −78° C. The mixture was stirred foranother hour at the same temperature before aqueous NH₄Cl (70 mL) wasadded to quench the reaction. The resulting mixture was extracted withEtOAc (150 mL×3) and the combined organic layers were washed withsaturated aqueous NaCl (150 mL), dried over Na₂SO₄, filtered, andconcentrated in vacuo. The crude residue was purified by silica gelchromatography (hexanes/EtOAc, 20:1˜5:1) to yield the crude residue (5g), which was further purified by preparative HPLC to yield Compound 14(4 g) as a yellow solid. LC-MS: 390 [M+H]⁺.

A solution of Compound 14 (4 g, 10.3 mmol) in concentrated HCl (50 mL)was heated under reflux overnight. The mixture was concentrated in vacuoand the resulting solid was washed with Et₂O (50 mL×2) to yield Compound15 (3.1 g) as a white solid HCl salt. LC-MS: 324 [M+H]⁺.

A solution of Compound 15 (3.1 g, 8.6 mmol) in HCl/EtOH (6.7M, 40 mL)was stirred overnight at 50° C. The resulting mixture was concentratedin vacuo and the residue was washed with ether (50 mL×2) to yield thetitle compound (2.9 g) as an off-white solid HCl salt. LC-MS: 352[M+H]⁺. ¹H NMR: (CD₃OD) 1.268 (t, J=6.9 Hz, 3H), 1.862-1.946 (m, 1H),2.068-2.143 (m, 1H), 3.104-3.199 (m, 2H), 3.769-3.809 (m, 1H),4.162-4.209 (m, 2H), 4.274-4.881 (m, 1H), 7.325 (dd, J=8.1, 2.1 Hz, 1H),7.522 (dd, J=8.3, 3.0 Hz, 1H), 7.696 (d, J=1.8 Hz, 1H).

Preparation 16:(2R,4R)-5-(4-Bromo-2-chlorophenyl)-4-t-butoxycarbonylamino-2-hydroxypentanoicAcid Ethyl Ester

(2R,4R)-4-Amino-5-(4-bromo-2-chlorophenyl)-2-hydroxypentanoic acid ethylester (160 mg, 460 μmol) and di-t-butyl dicarbonate (99.6 mg, 456 μmol)were mixed in DCM (5 mL) followed by the addition of DIPEA (120 μL, 680μmol). The mixture was stirred at room temperature for 1 hour. EtOAc wasadded and the mixture was washed with 1N HCl (10 mL) followed by aqueousNaHCO₃ (10 mL) and saturated aqueous NaCl (10 mL). The organic layer wasretained and dried over MgSO₄, then filtered and dried in vacuo to yieldthe title compound (200 mg).

Preparation 17:(2R,4R)-4-Amino-2-azido-5-(3,5′-dichloro-2′-fluorobiphenyl-4-yl)pentanoicAcid Ethyl Ester

A microwave flask was charged with(2R,4R)-5-(4-Bromo-2-chlorophenyl)-4-t-butoxycarbonylamino-2-hydroxypentanoicacid ethyl ester (400 mg, 887 μmol), 5-chloro-2-fluorophenylboronic acid(170 mg, 976 μmol), Na₂CO₃ (282 mg, 2.7 mmol), Pd(PPh₃)₄ (154 mg, 133μmol), EtOH (4 mL) and water (1 mL), then placed under nitrogen. Themixture was microwaved for 45 minutes at 110° C., at which time LCMSindicated the mass of the desired compound. The solvent was removed invacuo and the crude residue was purified by normal phase columnchromatography (20-100% EtOAc/hexanes) to yield Compound 1 (218 mg).

Compound 1 (218 mg, 436 μmol) was dissolved in DCM (5 mL).Methanesulfonyl chloride (37 μL, 479 μmol) was added, followed by Et₃N(152 μL, 1.1 mmol). The mixture was stirred at room temperature for 10minutes. EtOAc and a saturated aqueous NH₄Cl were added. The organiclayer was extracted, separated, dried over MgSO₄, filtered, andevaporated, to yield crude Compound 2, which was used directly in thenext step without purification.

Compound 2 (252 mg, 436 μmol) in DMF (4 mL) was combined with sodiumazide (85 mg, 1.3 mmol), and the resulting mixture was stirred at 50° C.for 7 hours. EtOAc and water were added. The organic layer wasextracted, separated and dried over MgSO₄, filtered, and evaporated. Thesolvent was evaporated and the residue was purified by normal phasecolumn chromatography (20-100% EtOAc/hexanes) to yield Compound 3 (181mg) as a yellow oil.

Compound 3 (162 mg, 308 μmol) was dissolved in MeCN (3 mL). A solutionof 4N HCl in dioxane (1.2 mL, 4.6 mmol) was added, and the mixture wasstirred at room temperature for 20 minutes, at which time LCMS indicatedthe mass of the desired compound. The mixture was then concentrated invacuo to yield the crude title compound as an HCl salt, which was usedwithout further purification.

Preparation 18:Oxodiperoxvmolyvbdenum(pyridine)-(hexamethylphosphorictriamide)

MbO₃→MbO₅.H₂O.(Me₂N)₃PO→MbO₅.(Me₂N)₃PO→MbO₅.Py.(Me₂N)₃PO

Molybdenum oxide (MoO₃; 30 g, 0.2 mol) and 30% hydrogen peroxide (150mL) were combined, with stirring. The reaction flask was placed in anoil bath equilibrated at 40° C. and heated until the internaltemperature reached 35° C. The heating bath was then removed andreplaced by a water bath to control the mildly exothermic reaction sothat an internal temperature of 35-40° C. was maintained. After theinitial exothermic period (˜30 minutes), the reaction flask was returnedto the 40° C. oil bath and stirred for a total of 3.5 hours to form ayellow solution with a small amount of suspended white solid. Aftercooling to 20° C., the solution was filtered and the resulting yellowfiltrate was cooled to 10° C. (with stirring) and hexamethylphosphorictriamide ((Me₂N)₃PO; HMPA; 37.3 g, 0.2 mol) was added dropwise over 5minutes, resulting in the formation of a yellow crystalline precipitate.Stirring was continued for a total of 15 minutes at 10° C., and theresidue was filtered and pressed dry. After 30 minutes in vacuo, thefilter cake was dissolved in MeOH (20 mL) and stirred at 40° C.Additional MeOH was slowly added until the solids dissolved. Thesaturated solution was cooled in the refrigerator, yielding a yellowsolid (appeared as needles). The solid mass was physically broken,filtered and washed with cold MeOH (20-30 mL) to yieldoxodiperoxymolybdenum(aqua) (hexamethylphosphoric triamide)(MoO₅.H₂O.HMPA, 46-50 g).

MoO₅.H₂O.HMPA was dried over phosphorus oxide in a vacuum desiccator,shielded from the light, for 24 hours at 0.2 mm Hg to yield a somewhathygroscopic yellow solid, MoO₅.HMPA. MoO₅.HMPA (36.0 g, 0.1 mol) wasdissolved in THF (150 mL) and the solution was filtered to remove anyprecipitate. The filtrate was then stirred at 20° C. while dry pyridine(8.0 g, 0.1 mol) was added over 10 minutes. The crystalline, yellowresidue was collected, washed with dry THF (25 mL) and anhydrous ether(200 mL) and dried in a vacuum desiccator (1 hour, 0.2 mm Hg) to yieldthe title compound (36-38 g; MoO₅.Py.HMPA) as a finely divided yellowsolid.

Preparation 19: (2R,4R)-4-Amino-5-biphenyl-4-yl-2-hydroxypentanoic AcidEthyl Ester and (2R,4S)-4-Amino-5-biphenyl-4-yl-2-hydroxypentanoic AcidEthyl Ester

To a stirred solution of(S)-2-biphenyl-4-ylmethyl-5-oxopyrrolidine-1-carboxylic acid t-butylester (4.4 g, 12.4 mmol) in anhydrous THF (70 mL) was added a solutionof 1 M LiHMDS in THF (28 mL) over 15 minutes at −65° C. under nitrogen.After stirring for 3 hours at −65° C., oxodiperoxymolybdenum (pyridine)(hexamethylphosphorictriamide) (9 g, 18.6 mmol) was added. The mixturewas stirred for another 2 hours at −35° C., then saturated aqueousNa₂S₂O₃ (60 mL) was added. The organic layer was collected and washedwith saturated aqueous NH₄Cl (3×60 mL) and saturated aqueous NaCl (2×60mL), then dried over Na₂SO₄, and the solvent was removed under reducedpressure to yield the crude residue which was further purified bychromatography (hexanes:EtOAc=5:1) to yield Compound 1 (1.8 g) as awhite solid. LC-MS: [2M+Na]: 757.

To a solution of Compound 1 (1.8 g, 5.0 mmol) in anhydrous DCM (50 mL)was added DMAP (122 mg, 1 mmol) and Et₃N (1.5 g, 14.9 mmol) at 0° C.under nitrogen. After stirring for 0.5 hour at 0° C., benzyl chloride(1.0 g, 7.4 mmol) was added over 15 minutes. The mixture was stirred foran additional 2 hours at 0° C., then saturated aqueous NaHCO₃ (50 mL)was added. The organic layer was collected and washed with saturatedaqueous NaHCO₃ (2×50 mL) and saturated aqueous NaCl (50 mL), then driedover Na₂SO₄. The mixture was filtered and the filtrate was concentratedto yield the crude residue which was further purified by chromatography(hexanes:EtOAc=4:1) to yield Compound 2A (471 mg) and Compound 2B (883mg) as white solids. LC-MS: [M+Na]: 494; [2M+Na]: 965.

Compound 2A: ¹H NMR (300 MHz, CDCl₃): δ (ppm)=8.02 (m, 2H), 7.57-7.25(m, 12H), 5.42 (m, 1H), 4.50 (m, 1H), 3.26-3.21 (m, 1H), 2.90 (m, 1H),2.58 (m, 1H), 2.15-2.05 (m, 1H), 1.62 (m, 9H).

Compound 2B: ¹H NMR (300 MHz, CDCl₃): δ (ppm)=8.06 (m, 2H), 7.58-7.18(m, 12H), 5.53-5.41 (m, 1H), 4.39 (m, 1H), 3.57-3.54 (m, 1H), 2.87-2.80(m, 1H), 2.48-2.44 (m, 1H), 1.98 (m, 1H), 1.63 (m, 9H).

To a stirred solution of Compound 2A (471 mg, 1 mmol) in anhydrous EtOH(10 mL) was added anhydrous K₂CO₃ (691 mg, 5 mmol) at room temperatureunder nitrogen. After stirring for 20 hours at room temperature, themixture was filtered. To the filtrate was added water (30 mL), DCM (30mL) and saturated aqueous NaCl (5 mL). The aqueous layer was separatedand extracted with DCM (30 mL×3). The combined organic layers werewashed with saturated aqueous NaCl (50 mL), dried over Na₂SO₄, andconcentrated to yield the crude residue which was further purified bychromatography (hexanes:EtOAc=6:1) to yield Compound 3 (275 mg) as awhite solid. LC-MS: [M+Na]⁺:436, [2M+Na]⁺:849.

To EtOH (5 mL) was added acetyl chloride (685 mg) at −30° C. Afterstirring for 1 hour at −30° C., a solution of Compound 3 (275 mg, 665μmol) in anhydrous EtOH (5 mL) was added. The mixture was heated to 25°C. and stirred for 3 hours at 25° C. After evaporation of the solvent,the residue was washed with cold anhydrous Et₂O (10 mL) to yield(2R,4R)-4-amino-5-biphenyl-4-yl-2-hydroxypentanoic acid ethyl ester (207mg) as a white solid HCl salt. LC-MS: [M+H]⁺:314, [2M+Na]⁺:649.

¹H NMR (300 MHz, CDCl₃): δ (ppm)=7.99 (m, 3H), 7.66-7.64 (m, 4H),7.48-7.35 (m, 5H), 6.08 (m, 1H), 4.21 (m, 1H), 4.09-4.05 (m, 2H), 3.52(m, 1H), 2.97-2.95 (m, 2H), 1.89-1.87 (m, 2H), 1.19-1.14 (m, 3H).

To a stirred solution of Compound 2B (883 mg, 1.9 mmol) in anhydrousEtOH (15 mL) was added anhydrous K₂CO₃ (1293 mg, 9.4 mmol) at roomtemperature under nitrogen. After stirring for 20 hours at roomtemperature, the mixture was filtered. To the filtrate was added water(30 mL), DCM (30 mL) and saturated aqueous NaCl (5 mL). The aqueouslayer was separated and extracted with DCM (30 mL×3). The combinedorganic layers were washed with saturated aqueous NaCl (50 mL), driedover Na₂SO₄, and concentrated to yield the crude residue which wasfurther purified by chromatography (hexanes:EtOAc=6:1) to yield Compound4 (524 mg) as a white solid. LC-MS: [M+Na]⁺:436, [2M+Na]⁺:849.

To EtOH (8 mL) was added acetyl chloride (1.3 g) at −30° C. Afterstirring for 1 hour at −30° C., a solution of Compound 4 (524 mg, 1.3mmol) in anhydrous EtOH (8 mL) was added. The mixture was heated to 25°C. and stirred for 3 hours at 25° C. After evaporation of the solvent,the residue was washed with cold anhydrous Et₂O (10 mL) to yield(2R,4S)-4-amino-5-biphenyl-4-yl-2-hydroxypentanoic acid ethyl ester (395mg) as a white solid HCl salt. LC-MS: [M+H]⁺:314, [2M+Na]⁺:649.

¹H NMR (300 MHz, CDCl₃): δ (ppm)=8.14 (m, 3H), 7.66-7.62 (m, 4H),7.47-7.31 (m, 5H), 5.87-5.85 (m, 1H), 4.34 (m, 1H), 4.08-4.00 (m, 2H),3.48 (m, 1H), 3.09 (m, 1H), 2.85-2.81 (m, 1H), 1.88 (m, 1H), 1.76 (m,1H), 1.15-1.10 (m, 3H).

Preparation 20:(2R,4R)-2-Amino-5-(2′-fluoro-biphenyl-4-yl)-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

1H-1,2,3-triazole-4-carboxylic acid (50.8 mg, 449 μmol) and HATU (171mg, 449 μmol) were dissolved in DMF (3 mL) and stirred for 15 minutes atroom temperature.(2R,4R)-4-Amino-2-azido-5-(5′-chloro-2′-fluorobiphenyl-4-yl)pentanoicacid ethyl ester (160 mg, 409 μmol) and DIPEA (214 μL, 1.2 mmol) wereadded, and the mixture was stirred at room temperature for 15 minutes,at which time LCMS indicated the mass of the desired compound. Themixture was then concentrated in vacuo to yield Compound 1, which wasused in the next step without purification.

Compound 1 (50 mg, 109 μmol) and palladium hydroxide (15.3 mg, 109 μmol)were stirred in dry MeOH (2 mL) and AcOH (2 mL). The reaction flask wasplaced in vacuo and flushed a few times with nitrogen, then placed underhydrogen and stirred at room temperature for 2 hours. LC/MS showedconversion to Compound 2, also yielding the title compound (having lostthe Cl atom on the ring). The hydrogen was removed in vacuo and theflask was purged with nitrogen. The mixture was filtered and thesolution was concentrated in vacuo to yield the crude title compound.

Preparation 21:(2R,4R)-4-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-methoxycarbonylaminopentanoicAcid Ethyl Ester

Compound 2 was prepared as described herein.

Compound 2 (210 mg, 428 μmol) and palladium hydroxide (60.1 mg, 428μmol) were dissolved in dry MeOH (5 mL) and AcOH (5 mL). The reactionflask was placed in vacuo and flushed a few times with nitrogen, thenplaced under hydrogen and stirred at room temperature for 1 hour. LC/MSshowed reaction completion. The hydrogen was removed in vacuo and theflask was purged with nitrogen. The mixture was filtered and thesolution was concentrated in vacuo to yield crude Compound 3, which wasused in the next step without purification.

Compound 3 (199 mg, 428 μmol) was dissolved in DCM (5 mL). Methylchloroformate (36.5 μL, 471 μmol) was added, followed by DIPEA (187 μL,1.2 mmol). The resulting mixture was stirred at room temperature for 10minutes (LC/MS showed reaction completion) then concentrated in vacuoand the residue was purified by normal phase column chromatography(20-100% EtOAc/hexanes) to yield Compound 4.

Compound 4 (30 mg, 57 μmol) was dissolved in MeCN (3 mL). A solution of4N HCl in dioxane (215 μL, 860 μmol) was added and the resulting mixturewas stirred at room temperature for 10 minutes (LC/MS showed reactioncompletion) then concentrated in vacuo to yield the crude title compoundas an HCl salt, which was used without further purification.

Preparation 22: (2S,4S)-4-Amino-5-biphenyl-4-yl-2-cyanomethylpentanoicAcid Ethyl Ester

(2S,4S)-5-Biphenyl-4-yl-4-t-butoxycarbonylamino-2-hydroxymethylpentanoicacid ethyl ester (450 mg, 1.1 mmol) was dissolved in DCM (2 mL).Methanesulfonyl chloride (98 μL, 1.3 mmol) was added, followed by Et₃N(293 μL, 2.1 mmol). The mixture was stirred at room temperature for 30minutes, then was purified by normal phase chromatography (0-100%EtOAc/hexanes) to yield Compound 1 (405 mg).

Compound 1 (200 mg, 396 μmol) in DMF (2 mL) was combined with sodiumcyanide (25 mg, 514 μmol), and the resulting mixture was stirred at 50°C. overnight. The reaction was quenched with water and extracted withEtOAc. The organic layer was washed (3×) with water, dried over Na₂SO₄,then concentrated under reduced pressure followed by purification bynormal phase chromatography (0-60% EtOAc/hexanes) to yield Compound 2(90 mg).

Compound 2 (90 mg, 206 μmol) was dissolved in MeCN and 4N HCl indioxane, and the mixture was stirred at room temperature for 10 minutes.The mixture was concentrated under reduced pressure to yield the titlecompound as an HCl salt, which was used without further purification.

Preparation 23:(2R,4S)-4-t-butoxycarbonylamino-5-(3′-fluorobiphenyl-4-yl)-2-hydroxymethylpentanoicAcid Ethyl Ester (compound 23a) and(2S,4S)-4-t-butoxycarbonylamino-5-(3′-fluorobiphenyl-4-yl)-2-hydroxymethylpentanoicAcid Ethyl Ester (compound 23-b)

To a solution of (R)-3-(4-bromophenyl)-2-t-butoxycarbonylamino propionicacid (50 g, 145 mmol), Meldrum's acid (23 g, 160 mmol) and DMAP (27.8 g,227 mmol) in anhydrous DCM (500 mL) was added a solution of DCC (33.3 g,161 mmol) in anhydrous DCM (200 mL) over 1 hour at −5° C. undernitrogen. The mixture was stirred at −5° C. for 8 hours, thenrefrigerated overnight, during which time tiny crystals ofdicyclohexylurea precipitated. After filtration, the mixture was washedwith 5% KHSO₄ (4×200 mL) and saturated aqueous NaCl (200 mL), then driedunder refrigeration with MgSO₄ overnight. The solution was evaporated toyield the crude Compound 1 (65.9 g) as a light yellow solid. LC-MS:[M+Na]⁺:493, [2M+Na]⁺:963.

To a solution of crude Compound 1 (65.9 g, 140 mmol) in anhydrous DCM (1L) was added AcOH (92.5 g, 1.5 mol) at −5° C. under nitrogen. Themixture was stirred at −5° C. for 0.5 hour, then NaBH₄ (13.2 g, 350mmol) was added in small portions over 1 hour. After stirring foranother 1 hour at −5° C., saturated aqueous NaCl (300 mL) was added. Theorganic layer was washed with saturated aqueous NaCl (2×300 mL) andwater (2×300 mL), dried over MgSO₄, filtered, and concentrated to yieldthe crude residue, which was further purified by chromatography(hexanes:EtOAc=6:1) to yield Compound 2 (33 g) as a light yellow solid.LC-MS: [M+Na]⁺:479, [2M+Na]⁺:935.

A solution of Compound 2 (33 g, 72.3 mmol) in anhydrous toluene (300 mL)was refluxed under nitrogen for 3 hours. After evaporation of thesolvent, the residue was purified by chromatography (hexanes:EtOAc=10:1)to yield Compound 3 (21 g) as a light yellow oil. LC-MS: [M+Na]⁺:377,[2M+Na]⁺:731.

To a solution of Compound 3 (21 g, 60 mmol) in 1,4-dioxane (250 mL) wasadded 3-fluorophenylboronic acid (8.8 g, 63 mmol) and Pd(dppf)₂Cl₂ (4.4g, 6 mmol) at room temperature under nitrogen. After stirring for 10minutes, a solution of K₂CO₃ (16.6 g, 120 mmol) in water (250 mL) wasadded. The mixture was heated to 100° C. and stirred overnight. Afterevaporation of the solvent, water (200 mL) was added and the materialwas extracted with EtOAc (3×200 mL). The combined organic layers werewashed with saturated aqueous NaCl (250 mL), dried over Na₂SO₄, andconcentrated to yield the crude residue, which was further purified bycolumn chromatography (hexanes:EtOAc=4:1) to yield Compound 4 (16.2 g)as a light yellow oil. LC-MS: [M+Na]⁺:392, [2M+Na]⁺:761.

A mixture of Compound 4 (16.2 g, 43.8 mmol) andt-butoxy-N,N,N′,N′-tetramethylmethanediamine (22.9 g, 131 mmol) washeated to 80° C. under nitrogen. After stirring for 3 hours at 80° C.,the mixture was diluted with EtOAc (300 mL), washed with 5 water (2×150mL) and saturated aqueous NaCl (2×150 mL), dried over MgSO₄, filtered,and evaporated to yield crude Compound 5 (18.6 g) as a light yellow oil.LC-MS: [M+H]⁺:425, [2M+H]⁺:849.

To a solution of crude Compound 5 (18.6 g, 43.8 mmol) in THF (200 mL)was added 1 M HCl (48 mL) at 0° C. under nitrogen. After stirring for 1hour at room temperature, the mixture was diluted with EtOAc (100 mL)and adjusted with saturated aqueous NaHCO₃ to pH 7. The aqueous layerwas extracted with EtOAc (2×150 mL) and the combined organic layers werewashed with water (2×150 mL) and saturated aqueous NaCl (150 mL), driedover MgSO₄, filtered, and evaporated to yield crude Compound 6 (17.4 g)as a yellow oil. LC-MS: [M+Na]⁺:420, [2M+Na]⁺:817.

To a solution of Compound 6 (17.4 g, 43.8 mmol) in anhydrous THF (300mL) was added anhydrous EtOH (30 mL) and AcOH (52.6 g, 867 mmol) at −5°C. under nitrogen. The mixture was stirred at −5° C. for 0.5 hour, thenNaBH₃CN (6.9 g, 110 mmol) was added in small portions over 1 hour. Afterstirring for one additional hour at −5° C., the mixture was adjustedwith saturated aqueous NaHCO₃ to pH 7. The aqueous layer was extractedwith EtOAc (2×200 mL) and the combined organic layers were washed withwater (2×150 mL) and saturated aqueous NaCl (150 mL), dried over MgSO₄,filtered, and concentrated to yield the crude residue, which was furtherpurified by chromatography (hexanes:EtOAc=6:1) to yield Compound 7 (6.7g) as a light yellow solid. LC-MS: [M+Na]⁺:422, [2M+Na]⁺:821.

To a solution of Compound 7 (6.7 g, 16.7 mmol) in anhydrous EtOH (500mL) was added anhydrous K₂CO₃ (4.6 g, 33.3 mmol) at 0° C. undernitrogen. After stirring for 1 hour at 0° C., the mixture was warmed toroom temperature and stirred for 16 hours. After filtration, thefiltrate was concentrated and the residue was diluted with water (150mL), DCM (200 mL) and saturated aqueous NaCl (50 mL). The layers wereseparated and the aqueous layer was extracted with DCM (2×150 mL). Thecombined organic layers were washed with saturated aqueous NaCl (2×200mL), dried over MgSO₄, and concentrated to yield the crude residue whichwas further purified by column chromatography (hexanes:EtOAc=5:1) toyield title compounds a and b (5.2 g) as light yellow solids.

Compound a: LC-MS: [M+Na]⁺=468, [2M+Na]⁺=913; ¹H NMR (300 MHz, CDCl₃):δ7.50-7.48 (m, 2H), 7.39-7.34 (m, 3H), 7.27-7.23 (m, 2H), 7.01 (m, 1H),4.42 (s, 1H), 4.20-4.13 (m, 2H), 3.90 (s, 1H), 3.78-3.74 (m, 2H),2.84-2.82 (m, 2H), 2.70 (s, 1H), 2.22 (s, 1H), 2.02-1.95 (m, 1H),1.59-1.50 (m, 1H), 1.39 (s, 9H), 1.27-1.23 (m, 3H).

Compound b: LC-MS: [M+Na]⁺=468, [2M+Na]⁺=913; ¹H NMR (300 MHz, CDCl₃):δ7.50-7.48 (m, 2H), 7.39-7.34 (m, 3H), 7.25-7.23 (m, 2H), 7.01 (m, 1H),4.42 (s, 1H), 4.19-4.13 (m, 2H), 3.90 (s, 1H), 3.79-3.75 (m, 2H),2.83-2.81 (m, 2H), 2.70 (m, 1H), 2.21 (s, 1H), 1.79-1.74 (m, 2H), 1.37(s, 9H), 1.29-1.23 (m, 3H).

Preparation 24: (R)-t-Butyl4-((5′-chloro-2′-fluoro-[1,1′-biphenyl]-4-yl)methyl)-1,2,3-oxathiazolidine-3-carboxylate2,2-dioxide

(4R)-t-Butyl4-((5′-chloro-2′-fluoro-[1,1′-biphenyl]-4-yl)methyl)-1,2,3-oxathiazolidine-3-carboxylate2-oxide (3.0 g, 7.0 mmol) was dissolved in MeCN (40 mL) to yield a clearsolution. The solution was cooled to 0° C. and ruthenium(iii) chloridemonohydrate (16 mg, 70 μmol) and sodium periodate (2.3 g, 10.6 mmol)were added. Water (20 mL) was added and the mixture was vigorouslystirred at 0° C. for 1 hour, yielding a thick slurry (analysis showed10% conversion). The mixture was then stirred at 5° C. overnight (almostcomplete conversion was observed). Additional water (20 mL) was addedand the mixture was stirred at room temperature for 1 hour. The mixturewas filtered and dried to yield the crude residue (3 g; purity 95%). Thecrude material was stirred in DCM (50 mL) for 2 hours. The mixture wasfiltered and the filtrate was concentrated to dryness to yield the titlecompound (2 g) as an off-white solid.

Preparation 25:(2S,4S)-4-t-Butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-methanesulfonyloxymethylpentanoicAcid Ethyl Ester

(2S,4S)-4-t-Butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-hydroxymethylpentanoicacid ethyl ester (250 mg, 521 μmol) was combined with DCM (2 mL), mesylchloride (48.7 μL, 625 μmol), and Et₃N (145 μL, 1.0 mmol) slowly. Themixture was stirred for 10 minutes and purified by normal phase columnchromatography (0-100% EtOAc/hexanes) to yield the title compound (240mg).

Preparation 26:(2S,4S)-4-t-Butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-(toluene-4-sulfonyloxymethyl)pentanoicAcid Ethyl Ester

(2S,4S)-4-t-Butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-hydroxymethylpentanoicacid ethyl ester (250 mg, 521 μmol) was combined with DCM (2 mL),p-toluenesulfonyl chloride (109 mg, 573 μmol), and Et₃N (145 μL, 1.0mmol) slowly. The mixture was stirred for 10 minutes and purified bynormal phase column chromatography (0-100% EtOAc/hexanes) to yield thetitle compound (267 mg).

Preparation 27:(2S,4S)-2-(4-Bromobenzenesulfonyloxymethyl)-4-t-butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)pentanoicAcid Ethyl Ester

(2S,4S)-4-t-Butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-hydroxymethylpentanoicacid ethyl ester (2.0 g, 4.2 mmol) was dissolved in dry DCM (10 mL) and4-bromobenzenesulfonyl chloride (1.4 g, 5.4 mmol), and Et₃N (1.2 L, 8.3mmol) was slowly added. The mixture was stirred for 90 minutes at roomtemperature, at which time LCMS indicated the mass of the desiredcompound. The crude solution was purified by normal phase columnchromatography (0-100% EtOAc/hexanes) to yield the title compound (2.2g).

Preparation 28:(2R,4R)-4-Amino-5-(5′-chloro-2′-fluorobiphen-4-yl)-2-(1-isobutyryloxy-ethoxycarbonylamino)pentanoicAcid Benzyl Ester

A mixture of(2R,4R)-2-azido-4-t-butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)pentanoicacid benzyl ester (2.6 g, 4.7 mmol), PPh₃ (1.5 g, 5.6 mmol) and THF/H₂O(50 mL/10 mL) was stirred at room temperature for two days. The solventwas concentrated in vacuo and purified by flash chromatography(DCM:MeOH=40:1) to yield compound 1 (1.3 g) as a colorless oil. LC-MS:m/z=527[(M⁺+1)].

To a mixture of Compound 1 (763 mg, 1.5 mmol), DIPEA (374 mg, 2.9 mmol),DMAP (177 mg, 1.5 mmol) and THF (6 mL) was added a solution of1-((4-nitrophenoxy) carbonyloxy)ethyl isobutyrate (645 mg, 2.2 mmol) inTHF (2 mL) at 25° C. The resulting mixture was stirred at roomtemperature overnight. The solvent was removed under reduced pressureand purified by flash chromatography (PE:EtOAc=4:1) to yield Compound 2(555 mg) as a white solid. LC-MS: m/z=707[(M⁺+Na)].

A suspension of Compound 2 (160 mg, 234 μmol) and ZnBr₂ (263 mg, 1.2mmol) in DCM (1.2 mL) was stirred at 25° C. for 12 hours, thenconcentrated and purified by preparative HPLC (50-70% MeCN in water with0.1% TFA) to yield the title compound (102 mg) as a white solid. LC-MS:m/z=585[(M⁺+1)]. ¹H NMR (300 MHz, CD₃OD) δ 7.32-7.49 (m, 11H), 7.17-7.23(m, 1H), 6.76-6.79 (m, 1H), 5.10-5.24 (m, 2H), 4.39-4.53 (m, 1H),3.59-3.64 (m, 1H), 2.91-3.20 (m, 2H), 2.45-2.57 (m, 1H), 2.18-2.28 (m,1H), 1.99-2.13 (m, 1H), 1.45-1.47 (m, 3H), 1.10-1.15 (m, 6H).

Preparation 29:(2S,4S)-4-Amino-2-(1-amino-1-methylethyl)-5-(5′-chloro-2′-fluorobiphenyl-4-yl)pentanoicAcid Ethyl Ester

To a solution of 2-methylpropane-2-sulfinic acid amide (6.6 g, 54 mmol)in THF (400 mL) was added acetone (15.8 g, 273 mmol) and titaniumethoxide (62 g, 273 mmol) at room temperature. The mixture was refluxedfor 24 hours and cooled to room temperature. Saturated aqueous NaHCO₃was added and the resulting solution was stirred for 5 minutes beforebeing filtered. The solids were washed with EtOAc (50 mL), and thecombined filtrates were transferred to a separatory funnel, where theaqueous portion was separated and extracted with EtOAc (2×50 mL). Thecombined organic phases were dried, filtered, and concentrated to yieldCompound 1 (8 g) as a colorless oil. ¹H NMR (300 MHz, CDCl₃) δ 2.31 (s,3H), 2.16 (s, 3H), 1.20 (s, 9H).

To a solution of(S)-2-(5′-chloro-2′-fluorobiphenyl-4-ylmethyl)-5-oxopyrrolidine-1-carboxylicacid t-butyl ester (1.1 g, 2.7 mmol) in anhydrous THF (20 mL) was addeddropwise NaHMDS (1.8 mL, 3.5 mmol) at −78° C. under nitrogen. Afterstirring at −78° C. for 1.5 hours, Compound 1 (570 mg, 3.5 mmol) wasadded dropwise. After stirring at this temperature for 2 hours, thereaction was quenched with saturated aqueous NH₄Cl (20 mL), warmed toroom temperature, and extracted with EtOAc (2×50 mL). The combinedorganic layers were washed with saturated aqueous NaCl (100 mL), driedover Na₂SO₄, filtered and concentrated to give the crude product whichwas purified by chromatography (PE:EtOAc=2:1) to yield Compound 2 (500mg) as a colorless oil. LC-MS: [M+Na]⁺: 587.

A mixture of Compound 2 (500 mg, 890 μmol) and K₂CO₃ (366 mg, 2.6 mmol)in EtOH (5 mL) was stirred at room temperature for 2 hours. The mixturewas filtered, the filtrated was acidified with HCl (1N) to pH 5 andextracted with EtOAc (3×20 mL). The organic phase was dried over Na₂SO₄,filtered, and concentrated to afford a residue, which was purified bycolumn chromatography (PE:EtOAc=2:1) to yield Compound 3 (450 mg) as acolorless oil. LC-MS: [M+H]⁺: 611.

A solution of Compound 3 (450 mg, 74 μmol) in 3.0 M HCl in dioxane (6mL) was stirred at room temperature for 3 hours. The mixture wasconcentrated, and the residue was purified by washing with Et₂O (7 mL)to yield the title compound (0.2 g) as a white solid. LC-MS: [M+H]⁺:407. ¹H NMR (300 MHz, CD₃OD) δ 7.57˜7.37 (m, 6H), 7.25˜7.18 (m, 1H),4.20 (m, 2H), 3.48 (m, 1H), 3.10˜2.98 (m, 3H), 2.14˜2.02 (m, 2H),1.45˜1.40 (m, 6H), 1.24˜1.18 (m, 3H).

Example 1:(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-4-[(3-ethylisoxazole-5-carbonyl)amino]-2-methoxymethylpentanoicAcid

To a stirred solution of 3-ethylisoxazole-5-carboxylic acid (17 mg, 50μmol) in HATU (23 mg, 60 μmol) and DMF, was added(2S,4S)-4-amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-methoxymethylpentanoicacid ethyl ester (384 mg, 60 μmol), followed by DIPEA (19 mg, 150 μmol).The mixture was stirred overnight to yield Compound 1, which was useddirectly in the next step.

Crude Compound 1 was dissolved in THF and 10N NaOH (65 μL, 650 μmol) andstirred at 50° C. overnight. The reaction was quenched with AcOH and thesolution was purified by preparative HPLC to yield the title compound(6.6 mg; purity 100%). MS m/z [M+H]⁺ calc'd for C₂₅H₂₆ClFN₂O₅, 489.15;found 489.2.

Example 2

Following the procedures described herein, and substituting theappropriate starting materials and reagents, these compounds wereprepared, either as the parent compound or as a TFA salt:

MS m/z [M + H]⁺ Ex. R⁶ Formula calcd found 1

C₂₂H₂₂ClFN₄O₄ 461.13 461.2 2

C₂₃H₂₁ClF₄N₄O₄ 529.12 529.2 3

C₂₆H₂₆ClF₂N₃O₄ 518.16 519.2 4

C₂₅H₂₅ClFN₃O₅ 502.15 502.2 5

C₂₃H₂₂ClFN₂O₆ 477.12 476 6

C₂₄H₂₄ClFN₂O₆ 491.13 491.2 7

C₂₃H₂₂ClFN₂O₅ 461.12 461.2 8

C₂₃H₂₂ClFN₂O₅ 461.12 461.2 9

C₂₆H₂₆ClFN₂O₅ 501.15 501.2 10

C₂₃H₂₂ClFN₂O₆ 477.12 476 11

C₂₂H₂₁ClFN₃O₆ 478.11 477 12

C₂₅H₂₃Cl₂FN₂O₄ 505.10 506.2 13

C₂₄H₂₃ClFN₃O₄ 472.14 472.2 14

C₂₆H₂₃ClF₄N₂O₄ 539.13 537 15

C₂₄H₂₄ClFN₂O₅ 475.14 475 16

C₂₅H₂₇ClFN₃O₅ 504.16 504

-   1.    (2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-methoxymethyl-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoic    acid-   2.    (2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-methoxymethyl-4-[(5-trifluoromethyl-1H-[1,2,4]triazole-3-carbonyl)amino]pentanoic    acid-   3.    (2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-4-[(5-cyclopropyl-4-fluoro-2H-pyrazole-3-carbonyl)amino]-2-methoxymethylpentanoic    acid-   4.    (2S,4S)-4-[(5-Acetyl-2H-pyrazole-3-carbonyl)-amino]-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-methoxymethylpentanoic    acid-   5.    (2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-4-[(3-hydroxyisoxazole-5-carbonyl)-amino]-2-methoxymethylpentanoic    acid-   6.    (2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-4-[(3-methoxyisoxazole-5-carbonyl)-amino]-2-methoxymethylpentanoic    acid-   7.    (2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-methoxymethyl-4-[(oxazole-2-carbonyl)amino]pentanoic    acid-   8.    (2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-methoxymethyl-4-[(oxazole-4-carbonyl)amino]pentanoic    acid-   9.    (2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-4-[(2-cyclopropyloxazole-4-carbonyl)amino]-2-methoxymethylpentanoic    acid-   10.    (2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-methoxymethyl-4-[(2-oxo-2,3-dihydro-oxazole-5-carbonyl)amino]pentanoic    acid-   11.    (2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-methoxymethyl-4-[(5-oxo-4,5-dihydro-[1,2,4]oxadiazole-3-carbonyl)amino]pentanoic    acid-   12.    (2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-4-[(5-chloro-pyridine-2-carbonyl)-amino]-2-methoxymethylpentanoic    acid-   13.    (2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-methoxymethyl-4-[(pyrimidine-2-carbonyl)amino]pentanoic    acid-   14.    (2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-methoxymethyl-4-[(5-trifluoromethylpyridine-2-carbonyl)amino]pentanoic    acid-   15.    (2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-methoxymethyl-4-[(5-methyloxazole-2-carbonyl)amino]pentanoic    acid-   16.    (2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-4-[(5-ethoxy-1H-pyrazole-3-carbonyl)amino]-2-methoxymethylpentanoic    acid

Example 3:(2S,4S)-5-(3′-Chlorobiphenyl-4-yl)-2-methoxymethyl-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

To a stirred solution of 3H-[1,2,3]triazole-4-carboxylic acid (20 mg, 50μmol) in HATU (23 mg, 60 μmol) and DMF (1 mL), was added(2S,4S)-4-amino-5-(3′-chlorobiphenyl-4-yl)-2-methoxymethyl-pentanoicacid ethyl ester (75 mg, 60 μmol), followed by DIPEA (19 mg, 150 μmol).The resulting mixture was stirred for 15 minutes to yield Compound 1,which was used directly in the next step.

Compound 1 was dissolved in THF and 10N NaOH (50 μL, 0.5 mmol) andstirred overnight at 50° C. The reaction was quenched with AcOH and thematerial was purified by preparative HPLC to yield the title compound(3.8 mg; purity 98%) as a TFA salt. MS m/z [M+H]⁺ calc'd forC₂₂H₂₃ClN₄O₄, 443.14; found 443.2.

Example 4

Following the procedures described herein, and substituting theappropriate starting materials and reagents, these compounds wereprepared, either as the parent compound or as a TFA salt:

MS m/z [M + H]⁺ Ex. R⁶ Formula calcd found 1

C₂₃H₂₂ClF₃N₄O₄ 511.13 511.2 2

C₂₃H₂₃ClN₂O₆ 459.12 458 3

C₂₂H₂₂ClN₃O₆ 460.12 459

-   1.    (2S,4S)-5-(3′-Chlorobiphenyl-4-yl)-2-methoxymethyl-4-[(5-trifluoromethyl-1H-[1,2,4]triazole-3-carbonyl)amino]pentanoic    acid-   2.    (2S,4S)-5-(3′-Chlorobiphenyl-4-yl)-4-[(3-hydroxy-isoxazole-5-carbonyl)amino]-2-methoxymethylpentanoic    acid-   3.    (2S,4S)-5-(3′-Chlorobiphenyl-4-yl)-2-methoxymethyl-4-[(5-oxo-4,5-dihydro-[1,2,4]oxadiazole-3-carbonyl)amino]pentanoic    acid

Example 5:(2S,4S)-5-Biphenyl-4-yl-2-methoxymethyl-4-[(1H-[1,2,3]-triazole-4-carbonyl)amino]pentanoicAcid

(2S,4S)-4-Amino-5-biphenyl-4-yl-2-methoxymethylpentanoic acid ethylester (16 mg, 47 μmol) was dissolved in DMF (0.3 mL).1H-1,2,3-Triazole-4-carboxylic acid (5.3 mg, 47 μmol) and HATU (18 mg,47 μmol) were added followed by DIPEA (25 μL, 141 μmol). The mixture wasstirred for 30 minutes and concentrated under reduced pressure to yieldCompound 1, which was used in the next step without purification.

Compound 1 (21 mg, 47 μmol) was dissolved in THF and NaOH (188 μL, 188μmol) and stirred for 2 hours at room temperature. AcOH was added toquench the reaction and the solution was purified by preparative HPLC toyield the title compound (6.5 mg; purity 95%) as a TFA salt. MS m/z[M+H]⁺ calc'd for C₂₂H₂₄N₄O₄, 409.18; found 409.2.

Example 6:(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-ethoxymethyl-4-[(5-trifluoromethyl-1H-[1,2,4]triazole-3-carbonyl)amino]pentanoicAcid

To a stirred solution of(2S,4S)-4-amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-ethoxymethylpentanoicacid ethyl ester (398 mg, 65 μmol) in DMF (2 mL) and HATU (23 mg, 60μmol), was added 5-methyl-1H-[1,2,4]triazole-3-carboxylic acid (22 mg,60 μmol), followed by DIPEA (19 μL, 150 μmol). The mixture was stirredat room temperature overnight to yield Compound 1, which was used in thenext step without purification.

To Compound 1 (65 μmol, 1 eq.) was added THF (0.4 mL) and 1N NaOH (65μL, 65 μmol, 10 eq.). The mixture was stirred at 50° C. overnight. AcOHwas added and the solution was purified by preparative HPLC to yield thetitle compound (4.7 mg; purity 99%) as a TFA salt. MS m/z [M+H]⁺ calc'dfor C₂₄H₂₃ClF₄N₄O₄, 543.13; found 543.2.

Example 7

Following the procedures described herein, and substituting theappropriate starting materials and reagents, these compounds wereprepared, either as the parent compound or as a TFA salt:

MS m/z [M + H]⁺ Ex. R⁶ Formula calcd found 1

C₂₃H₂₄ClFN₄O₄ 475.15 475.2 2

C₂₇H₂₈ClF₂N₃O₄ 532.17 533.2 3

C₂₆H₂₇ClFN₃O₅ 516.16 517.2 4

C₂₄H₂₄ClFN₂O₆ 491.13 490 5

C₂₆H₂₈ClFN₂O₅ 503.17 503.2 6

C₂₄H₂₄ClFN₂O₅ 475.14 475.2 7

C₂₄H₂₄ClFN₂O₅ 475.14 475.2 8

C₂₇H₂₈ClFN₂O₅ 515.17 515.2 9

C₂₄H₂₄ClFN₂O₆ 491.13 491.2 10

C₂₃H₂₃ClFN₃O₆ 492.13 491 11

C₂₅H₂₅ClFN₃O₄ 486.15 486.2

-   1.    (2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-ethoxymethyl-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoic    acid-   2.    (2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-4-[(5-cyclopropyl-4-fluoro-2H-pyrazole-3-carbonyl)amino]-2-ethoxymethylpentanoic    acid-   3.    (2S,4S)-4-[(5-Acetyl-2H-pyrazole-3-carbonyl)-amino]-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-ethoxymethylpentanoic    acid-   4.    (2S,4S)-5-(5′-Chloro-2′-fluoro-biphenyl-4-yl)-2-ethoxymethyl-4-[(3-hydroxy-isoxazole-5-carbonyl)amino]pentanoic    acid-   5.    (2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-ethoxymethyl-4-[(3-ethyl-isoxazole-5-carbonyl)amino]pentanoic    acid-   6.    (2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-ethoxymethyl-4-[(oxazole-2-carbonyl)amino]pentanoic    acid-   7.    (2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-ethoxymethyl-4-[(oxazole-4-carbonyl)amino]pentanoic    acid-   8.    (2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-4-[(2-cyclopropyloxazole-4-carbonyl)amino]-2-ethoxymethylpentanoic    acid-   9.    (2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-ethoxymethyl-4-[(2-oxo-2,3-dihydro-oxazole-5-carbonyl)amino]pentanoic    acid-   10.    (2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-ethoxymethyl-4-[(5-oxo-4,5-dihydro-[1,2,4]oxadiazole-3-carbonyl)amino]pentanoic    acid-   11.    (2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-ethoxymethyl-4-[(pyrimidine-2-carbonyl)amino]pentanoic    acid

Example 8:(2S,4S)-5-(3′-Chlorobiphenyl-4-yl)-2-ethoxymethyl-4-[(3-hydroxyisoxazole-5-carbonyl)amino]pentanoicAcid

To a stirred solution of(2S,4S)-4-amino-5-(3′-chlorobiphenyl-4-yl)-2-ethoxymethylpentanoic acidethyl ester (40 mg, 103 μmol) in HATU (46.8 mg, 123 μmol),3-hydroxy-isoxazole-5-carboxylic acid (13.2 mg, 133 μmol), and DMF (0.5mL), was added DIPEA (53.8 μL, 308 μmol). The mixture was stirred for 1hour, then concentrated under reduced pressure to yield crude Compound1, which was used in the next step without purification.

To Compound 1 (57 mg, 103 μmol) was added THF (0.8 mL) and 1N NaOH (412μL, 412 μmol). A few drops of EtOH were added to the solution and it wasstirred for 3 hours. The mixture was concentrated under reducedpressure. The residue was purified by reverse phase to yield the titlecompound (1 mg; purity 95%). MS m/z [M+H]⁺ calc'd for C₂₄H₂₅ClN₂O₆,473.14; found 472.

Example 9

Following the procedures described herein, and substituting theappropriate starting materials and reagents, these compounds wereprepared, either as the parent compound or as a TFA salt:

MS m/z [M + H]⁺ Ex. R⁶ Formula calcd found 1

C₂₃H₂₅ClN₄O₄ 457.16 456 2

C₂₆H₂₈ClN₃O₅ 498.17 497 3

C₂₄H₂₄ClF₃N₄O₄ 525.14 524 4

C₂₅H₂₇ClN₂O₆ 487.16 486 5

C₂₃H₂₄ClN₃O₆ 474.14 473

-   1.    (2S,4S)-5-(3′-Chlorobiphenyl-4-yl)-2-ethoxymethyl-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoic    acid-   2.    (2S,4S)-4-[(5-Acetyl-1H-pyrazole-3-carbonyl)-amino]-5-(3′-chlorobiphenyl-4-yl)-2-ethoxymethylpentanoic    acid-   3.    (2S,4S)-5-(3′-Chlorobiphenyl-4-yl)-2-ethoxymethyl-4-[(5-trifluoromethyl-1H-[1,2,4]triazole-3-carbonyl)amino]pentanoic    acid-   4.    (2S,4S)-5-(3′-Chlorobiphenyl-4-yl)-2-ethoxymethyl-4-[(3-methoxy-isoxazole-5-carbonyl)amino]pentanoic    acid-   5.    (2S,4S)-5-(3′-Chlorobiphenyl-4-yl)-2-ethoxymethyl-4-[(5-oxo-4,5-dihydro-[1,2,4]oxadiazole-3-carbonyl)amino]pentanoic    acid

Example 10:(2S,4S)-5-Biphenyl-4-yl-2-ethoxymethyl-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

To a stirred solution of(2S,4S)-4-amino-5-biphenyl-4-yl-2-ethoxymethylpentanoic acid ethyl ester(17 mg, 47 μmol) in DMF (0.3 mL), was added1H-1,2,3-triazole-4-carboxylic acid (5.3 mg, 47 μmol) and HATU (18 mg,47 μmol), followed by DIPEA (25 μL, 141 μmol). The mixture was stirredfor 30 minutes, then concentrated under reduced pressure to yield crudeCompound 1, which was used in the next step without purification.

To Compound 1 (21 mg, 47 μmol) was added THF (0.5 mL) and 1N NaOH (188μL, 188 μmol) was added and stirred for 2 hours at room temperature.AcOH was added and the solution was purified by preparative HPLC toyield the title compound (4.5 mg; purity 94%) as a TFA salt. MS m/z[M+H]⁺ calc'd for C₂₃H₂₆N₄O₄, 423.20; found 423.2.

Example 11:(2S,4S)-5-Biphenyl-4-yl-2-(2-hydroxyethoxymethyl)-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

To a stirred solution of(2S,4S)-4-amino-5-biphenyl-4-yl-2-(2-hydroxyethoxymethyl)pentanoic acidethyl ester (17 mg, 47 μmol) in DMF (0.3 mL), was added1H-1,2,3-triazole-4-carboxylic acid (5.3 mg, 47 μmol) and HATU (18 mg,47 μmol), followed by DIPEA (25 μL, 141 μmol). The mixture was stirredfor 30 minutes, then concentrated under reduced pressure to yield crudeCompound 1, which was used in the next step without purification.

To Compound 1 (22 mg, 47 μmol) was added THF (o.5 mL) and 1N NaOH (188μL, 188 μmol) was added and stirred for 2 hours at room temperature.AcOH was added and the solution was purified by preparative HPLC toyield the title compound (3.8 mg; purity 98%) as a TFA salt. MS m/z[M+H]⁺ calc'd for C₂₃H₂₆N₄O₅, 439.19; found 439.2.

Example 12:(2S,4S)-5-Biphenyl-4-yl-2-(3-hydroxypropoxymethyl)-4-[(1H-[1.2.3]triazole-4-carbonyl)amino]pentanoicAcid

To a stirred solution of(2S,4S)-4-amino-5-biphenyl-4-yl-2-(3-hydroxypropoxymethyl)pentanoic acidethyl ester (18 mg, 47 μmol) in DMF (0.3 mL), was added1H-1,2,3-triazole-4-carboxylic acid (5.3 mg, 47 μmol) and HATU (18 mg,47 μmol), followed by DIPEA (25 μL, 141 μmol). The mixture was stirredfor 30 minutes, then concentrated under reduced pressure to yield crudeCompound 1, which was used in the next step without purification.

To Compound 1 (23 mg, 47 μmol) was added THF (0.5 mL) and 1N NaOH (188μL, 188 μmol) was added and stirred for 2 hours at room temperature.AcOH was added and the solution was purified by preparative HPLC toyield the title compound (1.3 mg; purity 100%) as a TFA salt. MS m/z[M+H]⁺ calc'd for C₂₄H₂₈N₄O₅, 453.21; found 453.2.

Example 13:(2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

1H-1,2,3-triazole-4-carboxylic acid (15.9 mg, 141 μmol) and HATU (53.5mg, 141 μmol) were dissolved in DMF (2 mL) and stirred for 15 minutes atroom temperature.(2R,4R)-4-Amino-2-azido-5-(5′-chloro-2′-fluorobiphenyl-4-yl)pentanoicacid ethyl ester (50 mg, 128 μmol) and DIPEA (67 μL, 384 μmol) wereadded, and the mixture was stirred at room temperature for 15 minutesthen concentrated in vacuo and the residue was dissolved in EtOH (2 mL).An aqueous solution of 1N NaOH (1.3 mL, 1.3 mmol) was added, and themixture was stirred at room temperature for 30 minutes then concentratedin vacuo and the residue was purified by reverse phase chromatography toyield Compound 1 (45 mg).

Compound 1 (45 mg, 98 μmol) and palladium hydroxide (2.1 mg, 15 μmol)were stirred at room temperature in dry MeOH (2 mL) and AcOH (2 mL). Thereaction flask was placed under hydrogen and stirred at room temperaturefor 30 minutes. The hydrogen was removed in vacuo and the flask waspurged with nitrogen. The mixture was filtered and the solution wasconcentrated in vacuo. The residue was purified by reverse phasechromatography in the absence of TFA to yield the title compound (27 mg;purity 96%). MS m/z [M+H]⁺ calc'd for C₂₀H₁₉ClFN₅O₃, 432.12; found432.2.

Example 14a:(2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid Ethyl Ester

(2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicacid (17 mg, 39 μmol) was dissolved in EtOH (5 mL). A solution of 4N HClin dioxane (148 μL, 0.6 mmol) was added. The resulting mixture wasstirred at room temperature for 2 days, at which time LCMS indicated themass of the desired compound. The mixture was concentrated in vacuo andthe residue was purified by reverse phase chromatography to yield thetitle compound (10 mg; purity 99%) as a white powder TFA salt. MS m/z[M+H]⁺ calc'd for C₂₂H₂₃ClFN₅O₃, 460.15; found 460.

Example 14b:(2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid Hexyl Ester

(2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicacid (10 mg, 23 μmol) was dissolved in 1-hexanol (500 mL; 237 mg, 2.3mol). A solution of 4N HCl in dioxane (174 μL, 0.7 mmol) was added. Theresulting mixture was stirred overnight at 50° C. then concentrated invacuo and the residue was purified by reverse phase chromatography toyield the title compound (4.1 mg; purity 95%) as a TFA salt. MS m/z[M+H]⁺ calc'd for C₂₆H₃₁ClFN₅O₃, 516.21; found 516.

Example 15:(2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphen-4-yl)-4-[(4-isopropyloxazole-2-carbonyl)amino]pentanoicAcid

4-Isopropyloxazole-2-carboxylic acid (21.8 mg, 141 μmol) and HATU (53.5mg, 141 μmol) were dissolved in DMF (3.5 mL) and stirred for 15 minutesat room temperature.(2R,4R)-4-Amino-2-azido-5-(5′-chloro-2′-fluorobiphenyl-4-yl)pentanoicacid ethyl ester (50 mg, 128 μmol) and DIPEA (67 μL, 384 μmol) wereadded, and the mixture was stirred at room temperature for 15 minutes,at which time LCMS indicated the mass of the desired compound. Themixture was concentrated in vacuo and the residue was dissolved in EtOH(3 mL). An aqueous solution of 1N NaOH (1.3 mL, 1.3 mmol) was added, andthe mixture was stirred at room temperature for 1 hour, at which timeLCMS indicated the mass of the desired compound. The mixture wasconcentrated in vacuo. An aqueous solution of 1N HCl was added, and thecrude residue was extracted with EtOAc. The organic layers werecombined, dried over MgSO₄, filtered and evaporated to yield Compound 1,which was used in the next step without purification.

Compound 1 (65 mg, 130 μmol) and palladium (10 wt % on carbon, wet, 50g, 65 μmol) were mixed in dry EtOAc (3 mL) and AcOH (3 mL). The reactionflask was placed under hydrogen and stirred at room temperature for 3hours. The hydrogen was removed in vacuo and the flask was purged withnitrogen. The mixture was filtered and the solution was concentrated invacuo. The residue was purified by preparative HPLC to yield the titlecompound (15 mg; purity 100%) as a TFA salt. MS m/z [M+H]⁺ calc'd forC₂₄H₂₅ClFN₃O₄, 474.15, found 474.2.

Example 16

Following the procedures described herein, and substituting theappropriate starting materials and reagents, these compounds wereprepared, either as the parent compound or as a TFA salt:

MS m/z [M + H]⁺ Ex. R¹ R⁶ Formula calcd found 1 H

C₂₃H₂₃ClFN₃O₄ 460.14 460.2 2 H

C₂₄H₂₅ClFN₃O₄ 474.15 474.2 3 H

C₂₂H₂₁ClFN₃O₄ 446.12 446.2 4 H

C₂₄H₂₃ClFN₃O₄ 472.14 472.2 5 H

C₂₃H₂₃ClFN₃O₅ 476.13 476.2 6 H

C₂₄H₂₅ClFN₃O₄ 474.15 474.2 7 H

C₂₃H₂₀Cl₂FN₃O₃ 476.09 476.2 8 H

C₂₁H₁₉ClFN₃O₃S 448.08 448.2 9 H

C₂₃H₂₂ClFN₄O₄ 473.13 473.1 10 —CH₂CH₃

C₂₅H₂₆ClFN₄O₄ 501.16 501 11 —CH₂CH₃

C₂₃H₂₃ClFN₃O₅ 476.13 475 12 —CH₂CH₃

C₂₃H₂₃ClFN₃O₅ 476.13 475 13 —CH—(CH₃)₂

C₂₄H₂₅ClFN₃O₅ 490.15 490 14 —(CH₂)₃—CH₃

C₂₅H₂₇ClFN₃O₅ 504.16 504 15 H

C₂₀H₁₈ClFN₄O₅ 449.10 449.2 16 H

C₂₀H₁₈ClFN₄O₅ 449.10 449.1 17 —CH₂CH₃

C₂₂H₂₂ClFN₄O₅ 477.13 477 18 H

C₂₄H₂₅ClFN₅O₄ 502.16 502.2 19 —CH₂CH₃

C₂₆H₂₉ClFN₅O₄ 530.19 530.2 20 H

C₂₂H₂₁ClF₂N₄O₃ 463.13 463.2 21 H

C₂₃H₂₃ClFN₅O₄ 488.14 488.2 22 —CH₂CH₃

C₂₅H₂₇ClFN₅O₄ 516.17 516 23 H

C₂₈H₂₅ClF₂N₄O₃ 539.16 539.2 24 H

C₂₇H₂₂Cl₂FN₃O₄ 542.10 542.2 25 H

C₂₄H₂₀Cl₂FN₅O₃ 516.09 516.2 26 H

C₂₄H₂₀Cl₂FN₅O₃ 516.09 516.2 27 H

C₂₁H₁₉ClFN₃O₅ 448.10 448.0 28 H

C₂₁H₁₉ClFN₃O₅ 448.10 448.0 29 H

C₂₂H₂₀ClFN₄O₃ 443.12 443.0 30 —CH₂CH₃

C₂₄H₂₄ClFN₄O₃ 471.15 471.1 31 H

C₂₁H₁₉ClFN₃O₅ 448.10 448.0 32 —CH₂CH₃

C₂₃H₂₃ClFN₃O₅ 476.13 476.1 33 H

C₂₅H₂₂ClFN₆O₃ 509.14 509.1 34 —CH₂CH₃

C₂₇H₂₆ClFN₆O₃ 537.17 537.1 35 H

C₂₆H₂₃ClFN₅O₄ 524.14 524.1 36 —CH₂CH₃

C₂₈H₂₇ClFN₅O₄ 552.17 552.1

-   1.    (2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(3-ethylisoxazole-5-carbonyl)-amino]pentanoic    acid-   2.    (2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(5-propylisoxazole-3-carbonyl)-amino]pentanoic    acid-   3.    (2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(5-methyloxazole-2-carbonyl)-amino]pentanoic    acid-   4.    (2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(2-cyclopropyloxazole-4-carbonyl)amino]pentanoic    acid-   5.    (2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(2-ethoxyoxazole-4-carbonyl)-amino]pentanoic    acid-   6.    (2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(2-propyloxazole-4-carbonyl)-amino]pentanoic    acid-   7.    (2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(5-chloropyridine-2-carbonyl)-amino]pentanoic    acid-   8.    (2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(isothiazole-5-carbonyl)amino]-pentanoic    acid-   9.    (2R,4R)-4-[(5-Acetyl-2H-pyrazole-3-carbonyl)amino]-2-amino-5-(5′-chloro-2′-fluoro-biphenyl-4-yl)pentanoic    acid-   10.    (2R,4R)-4-[(5-Acetyl-2H-pyrazole-3-carbonyl)amino]-2-amino-5-(5′-chloro-2′-fluoro-biphenyl-4-yl)pentanoic    acid ethyl ester-   11.    (2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(3-hydroxyisoxazole-5-carbonyl)amino]pentanoic    acid ethyl ester-   12.    (2S,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(3-hydroxyisoxazole-5-carbonyl)amino]pentanoic    acid ethyl ester-   13.    (2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(3-hydroxyisoxazole-5-carbonyl)amino]pentanoic    acid isopropyl ester-   14.    (2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(3-hydroxyisoxazole-5-carbonyl)amino]pentanoic    acid butyl ester-   15.    (2S,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(5-oxo-4,5-dihydro-[1,2,4]oxadiazole-3-carbonyl)amino]pentanoic    acid-   16.    (2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(5-oxo-4,5-dihydro-[1,2,4]oxadiazole-3-carbonyl)amino]pentanoic    acid-   17.    (2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(5-oxo-4,5-dihydro-[1,2,4]oxadiazole-3-carbonyl)amino]pentanoic    acid ethyl ester-   18.    (2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(5-dimethylcarbamoyl-2H-pyrazole-3-carbonyl)amino]pentanoic    acid-   19.    (2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(5-dimethylcarbamoyl-2H-pyrazole-3-carbonyl)amino]pentanoic    acid ethyl ester-   20.    (2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(4-fluoro-5-methyl-2H-pyrazole-3-carbonyl)amino]pentanoic    acid-   21.    (2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(5-methylcarbamoyl-2H-pyrazole-3-carbonyl)amino]pentanoic    acid-   22.    (2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(5-methylcarbamoyl-2H-pyrazole-3-carbonyl)amino]pentanoic    acid ethyl ester-   23.    (2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(4-fluoro-5-o-tolyl-2H-pyrazole-3-carbonyl)amino]pentanoic    acid-   24.    (2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-{[3-(2-chlorophenyl)-isoxazole-5-carbonyl]amino}pentanoic    acid-   25.    (2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(7-chloro-[1,2,4]triazolo[1,5-a]pyridine-2-carbonyl)amino]pentanoic    acid-   26.    (2S,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(7-chloro-[1,2,4]triazolo[1,5-a]pyridine-2-carbonyl)amino]pentanoic    acid-   27.    (2S,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(3-hydroxyisoxazole-5-carbonyl)amino]pentanoic    acid-   28.    (2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(3-hydroxyisoxazole-5-carbonyl)amino]pentanoic    acid-   29.    (2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(pyrimidine-2-carbonyl)-amino]pentanoic    acid-   30.    (2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(pyrimidine-2-carbonyl)-amino]pentanoic    acid ethyl ester-   31.    (2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(2-oxo-2,3-dihydro-oxazole-4-carbonyl)amino]pentanoic    acid-   32.    (2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(2-oxo-2,3-dihydro-oxazole-4-carbonyl)amino]pentanoic    acid ethyl ester-   33.    (2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(5-pyrazin-2-yl-2H-pyrazole-3-carbonyl)amino]pentanoic    acid-   34.    (2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(5-pyrazin-2-yl-2H-pyrazole-3-carbonyl)amino]pentanoic    acid ethyl ester-   35.    (2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(5-oxo-1-phenyl-4,5-dihydro-1H-[1,2,4]triazole-3-carbonyl)amino]pentanoic    acid-   36.    (2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(5-oxo-1-phenyl-4,5-dihydro-1H-[1,2,4]triazole-3-carbonyl)amino]pentanoic    acid ethyl ester

Example 17:(2R,4R)-2-Amino-5-(3,5′-dichloro-2′-fluorobiphenyl-4-yl)-4-[(4-isopropyloxazole-2-carbonyl)amino]pentanoicAcid

4-Isopropyloxazole-2-carboxylic acid (10.4 mg, 67 μmol) and HATU (25.6mg, 67 μmol) were dissolved in DMF (2 mL) and stirred for 15 minutes atroom temperature.(2R,4R)-4-Amino-2-azido-5-(3,5′-dichloro-2′-fluorobiphenyl-4-yl)pentanoicacid ethyl ester (26 mg, 61 μmol) and DIPEA (32 μL, 183 μmol) wereadded, and the mixture was stirred at room temperature for 15 minutes,at which time LCMS indicated the mass of the desired compound. Themixture was concentrated in vacuo and the residue was dissolved in EtOH(2 mL). An aqueous solution of 1N NaOH (611 μL, 611 μmol) was added, andthe mixture was stirred at room temperature for 30 minutes, at whichtime LCMS indicated the mass of the desired compound. The mixture wasconcentrated in vacuo and the residue was diluted in an aqueous solutionof 1N HCl and extracted twice with EtOAc. The organic layers werecombined, dried over MgSO₄, filtered and evaporated, to yield crudeCompound 1, which was directly in the next step.

Compound 1 (30 mg, 56 μmol) and palladium (10 wt % on carbon, wet 50 g;5 mg, 5.6 μmol) were stirred at room temperature in dry EtOAc (2 mL) andAcOH (2 mL). The reaction flask was placed under hydrogen and stirred atroom temperature for 30 minutes. The hydrogen was removed in vacuo andthe flask was purged with nitrogen. The mixture was filtered and thesolution was concentrated in vacuo. The residue was purified bypreparative HPLC to yield the title compound (1.4 mg; purity 80%) as aTFA salt. MS m/z [M+H]⁺ calc'd for C₂₄H₂₄Cl₂FN₃O₄, 508.11; found 509.0.

Example 18

Following the procedures described herein, and substituting theappropriate starting materials and reagents, these compounds wereprepared as a TFA salt:

MS m/z [M + H]⁺ Ex. R⁶ Formula calcd found 1

C₂₄H₂₄Cl₂FN₃O₄ 508. 11 508.2 2

C₂₄H₂₄Cl₂FN₃O₄ 508. 11 508.2 3

C₂₂H₂₀Cl₂FN₃O₄ 480.08 480.0 4

C₂₂H₂₀Cl₂FN₃O₄ 480.08 480.0 5

C₂₃H₂₂Cl₂FN₃O₄ 494.10 494.2 6

C₂₃H₂₂Cl₂FN₃O₄ 494.10 494.2 7

C₂₃H₂₂Cl₂FN₃O₄ 510.09 510.2 8

C₂₃H₂₂Cl₂FN₃O₅ 510.09 510.2 9

C₂₄H₂₂Cl₂FN₃O₄ 506.10 506.2 10

C₂₄H₂₂Cl₂FN₃O₄ 506.10 506.2 11

C₂₂H₂₀Cl₂FN₃O₅ 496.08 496.0 12

C₂₂H₂₀Cl₂FN₃O₅ 496.08 496.0

-   1.    (2S,4R)-2-Amino-5-(3,5′-dichloro-2′-fluorobiphenyl-4-yl)-4-[(4-isopropyloxazole-2-carbonyl)amino]pentanoic    acid-   2.    (2R,4R)-2-Amino-5-(3,5′-dichloro-2′-fluorobiphenyl-4-yl)-4-[(2-propyloxazole-4-carbonyl)amino]pentanoic    acid-   3.    (2R,4R)-2-Amino-5-(3,5′-dichloro-2′-fluorobiphenyl-4-yl)-4-[(5-methyloxazole-2-carbonyl)amino]pentanoic    acid-   4.    (2S,4R)-2-Amino-5-(3,5′-dichloro-2′-fluorobiphenyl-4-yl)-4-[(5-methyloxazole-2-carbonyl)amino]pentanoic    acid-   5.    (2R,4R)-2-Amino-5-(3,5′-dichloro-2′-fluorobiphenyl-4-yl)-4-[(3-ethylisoxazole-5-carbonyl)amino]pentanoic    acid-   6.    (2S,4R)-2-Amino-5-(3,5′-dichloro-2′-fluorobiphenyl-4-yl)-4-[(3-ethylisoxazole-5-carbonyl)amino]pentanoic    acid-   7.    (2R,4R)-2-Amino-5-(3,5′-dichloro-2′-fluorobiphenyl-4-yl)-4-[(5-methoxymethylisoxazole-3-carbonyl)amino]pentanoic    acid-   8.    (2S,4R)-2-Amino-5-(3,5′-dichloro-2′-fluorobiphenyl-4-yl)-4-[(5-methoxymethylisoxazole-3-carbonyl)amino]pentanoic    acid-   9.    (2R,4R)-2-Amino-4-[(5-cyclopropyl-isoxazole-3-carbonyl)-amino]-5-(3,5′-dichloro-2′-fluorobiphenyl-4-yl)pentanoic    acid-   10.    (2S,4R)-2-Amino-4-[(5-cyclopropyl-isoxazole-3-carbonyl)-amino]-5-(3,5′-dichloro-2′-fluorobiphenyl-4-yl)pentanoic    acid-   11.    (2R,4R)-2-Amino-5-(3,5′-dichloro-2′-fluoro-biphenyl-4-yl)-4-[(5-methoxyoxazole-2-carbonyl)amino]pentanoic    acid-   12.    (2S,4R)-2-Amino-5-(3,5′-dichloro-2′-fluoro-biphenyl-4-yl)-4-[(5-methoxyoxazole-2-carbonyl)amino]pentanoic    acid

Example 19:(2S,4S)-2-Aminomethyl-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid Ethyl Ester

To a stirred solution of(2S,4S)-4-t-butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-hydroxymethylpentanoicacid ethyl ester (525 mg, 1.1 mmol) in DCM (2 mL), was addedmethanesulfonyl chloride (102 μL, 1.3 mmol), followed by the slowaddition of Et₃N (305 μL, 2.2 mmol). The mixture was stirred at roomtemperature for 30 minutes and was then purified by normal phasechromatography (0-100% EtOAc/hexanes) to yield Compound 1 (405 mg).

Compound 1 (325 mg, 582 μmol) was dissolved in DMF (2 mL) and combinedwith sodium azide (41.6 mg, 641 μmol), and the resulting mixture wasstirred at room temperature for 3 hours. The reaction was quenched withwater and extracted with EtOAc. The organic layer was washed (3×) withwater, dried over Na₂SO₄, then concentrated under reduced pressure, andthe residue purified by normal phase column chromatography (0-100%EtOAc/hexanes) to yield Compound 2 (290 mg).

Compound 2 (290 mg, 574 μmol) was dissolved in MeCN (3 mL) and 4N HCl indioxane (1 mL), and the mixture was stirred at room temperature for 10minutes. The mixture was concentrated under reduced pressure to yieldcrude Compound 3 as an HCl salt.

1H-1,2,3-triazole-5-carboxylic acid (55.9 mg, 494 μmol) was combinedwith HATU (188 mg, 494 μmol) in DMF (0.5 mL) and stirred for 10 minutes;DIPEA (1.5 eq.) was added and the mixture was stirred for 1 minute.Compound 3 (200 mg, 494 μmol) was dissolved in DMF (1 mL) and DIPEA (259μL, 1.5 mmol) was added, followed by addition of the activated acidsolution. The mixture was stirred for 30 minutes and the solvent wasevaporated. The mixture was purified by normal phase chromatography(0-100% EtOAc/hexanes) to yield Compound 4 (100 mg).

Compound 4 (100 mg, 0.2 mmol) was combined with PdOH₂/C (21.3 mg, 40μmol) and EtOAc (1 mL) with 12N HCl (50 μL). Oxygen was removed in vacuoand the flask placed under hydrogen (1 atm), then stirred at roomtemperature for 6 hours. The hydrogen was removed in vacuo and the flaskwas purged with nitrogen. The reaction was quenched with AcOH andpurified by reverse phase chromatography to yield the title compound (50mg) as a TFA salt. MS m/z [M+H]⁺ calc'd for C₂₃H₂₅ClFN₅O₃, 474.16; found474.

Example 20:(2S,4S)-2-Aminomethyl-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

(2S,4S)-2-Aminomethyl-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicacid ethyl ester (40 mg, 84 μmol) was dissolved in THF (1 mL), 1N LiOH(253 μL, 253 μmol) and 3 drops of MeOH and stirred at room temperature.The reaction was determined to be complete after 30 minutes and AcOH wasadded. The crude residue was purified (reverse phase chromatography) toyield the title compound (20 mg; purity 98%) as a TFA salt. MS m/z[M+H]⁺ calc'd for C₂₁H₂₁ClFN₅O₃, 446.13; found 446.

Example 21

Following the procedures described herein, and substituting theappropriate starting materials and reagents, these compounds wereprepared as TFA salts:

MS m/z [M + H]⁺ Ex. R¹ R⁶ Formula calcd found 1 H

C₂₄H₂₅ClFN₃O₄ 474.15 473 2 H

C₂₅H₂₅ClN₃O₄ 486.15 485 3 H

C₂₃H₂₃ClFN₃O₄ 460.14 459 4 H

C₂₄H₂₅ClFN₃O₅ 490.15 489 5 H

C₂₃H₂₃ClFN₃O₄ 460.14 459 6 H

C₂₃H₂₃ClFN₃O₃S 476.11 475 7 H

C₂₂H₂₁ClFN₃O₃S 462.10 462 8 —CH(CH₃)₂

C₂₄H₂₇ClFN₅O₃ 488.18 489 9 —(CH₂)₃—CH₃

C₂₅H₂₉ClFN₅O₃ 502.19 503 10 —(CH₂)₅—CH₃

C₂₇H₃₃ClFN₅O₃ 530.23 531

-   1.    (2S,4S)-2-Aminomethyl-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(3-ethyl-isoxazole-5-carbonyl)amino]pentanoic    acid-   2.    (2S,4S)-2-Aminomethyl-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(2-cyclopropyl-oxazole-4-carbonyl)amino]pentanoic    acid-   3.    (2S,4S)-2-Aminomethyl-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(5-methyl-oxazole-2-carbonyl)amino]pentanoic    acid-   4.    (2S,4S)-2-Aminomethyl-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(2-ethoxy-oxazole-4-carbonyl)amino]pentanoic    acid-   5.    (2S,4S)-2-Aminomethyl-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(2-methyloxazole-4-carbonyl)amino]pentanoic    acid-   6.    (2S,4S)-2-Aminomethyl-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[1(3-methylisothiazole-5-carbonyl)amino]pentanoic    acid-   7.    (2S,4S)-2-Aminomethyl-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(isothiazole-4-carbonyl)amino]pentanoic    acid-   8.    (2S,4S)-2-Aminomethyl-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoic    acid isopropyl ester-   9.    (2S,4S)-2-Aminomethyl-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoic    acid butyl ester-   10.    (2S,4S)-2-Aminomethyl-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(1H-

Example 22:(2S,4S)-2-Aminomethyl-5-biphenyl-4-yl-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

(2S,4S)-5-Biphenyl-4-yl-4-t-butoxycarbonylamino-2-hydroxymethylpentanoicacid ethyl ester (450 mg, 1.1 mmol) was dissolved in DCM (2 mL) andmethanesulfonyl chloride (98 μL, 1.3 mmol) was added, followed by Et₃N(293 μL, 2.1 mmol). The mixture was stirred at room temperature for 30minutes, and the solution was purified by normal phase chromatography(0-100% EtOAc/hexanes) to yield Compound 1 (405 mg).

Compound 1 (200 mg, 396 μmol) in DMF (2 mL) was combined with sodiumazide (33 mg, 514 μmol), and the resulting mixture was stirred at 50° C.overnight. The reaction was quenched with water and extracted withEtOAc. The organic layer was washed (3×) with water, dried over Na₂SO₄,then concentrated under reduced pressure and purified by normal phasechromatography (0-60% EtOAc/hexanes) to yield Compound 2 (115 mg).

Compound 2 (93 mg, 206 μmol) was dissolved in MeCN and 4N HCl indioxane, and the mixture was stirred at room temperature for 10 minutes.The mixture was concentrated under reduced pressure to yield crudeCompound 3 as an HCl salt, which was used directly in the next step.

Compound 3 (30 mg, 199 μmol) was combined with3H-[1,2,3]triazole-4-carboxylic acid (22 mg, 199 μmol), HATU (76 mg, 199μmol) and DIPEA (104 μL, 596 μmol) in DMF (1 mL) and stirred at roomtemperature for 20 minutes then concentrated in vacuo and the cruderesidue was purified by normal phase chromatography (0-100%EtOAc/hexanes). The intermediate (30 mg, 67 μmol) was dissolved in THF(1 mL) and 10N NaOH (268 μL, 268 μmol) and stirred at room temperaturefor 1 hour. The mixture was acidified with AcOH and purified bypreparative HPLC to yield Compound 4 (10 mg).

Compound 4 (50 mg, 119 μmol) was combined with PdOH₂/C (17 mg, 119 μmol)in MeOH. Oxygen was removed in vacuo and the solution was placed underhydrogen (1 atm), then stirred for 2 hours. The flask was purged withnitrogen. The reaction was quenched with AcOH, filtered, and purified byreverse phase chromatography to yield the title compound (10 mg; purity95%) as a TFA salt. MS m/z [M+H]⁺ calc'd for C₂₁H₂₃N₅O₃, 394.18; found394.

Example 23:(2R,4S)-2-(2-Aminoethyl)-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(5-methyloxazole-2-carbonyl)amino]pentanoicAcid

To a solution of(2S,4S)-4-t-Butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-hydroxymethylpentanoicacid ethyl ester (530 mg, 1.1 mmol) in DCM (5.5 mL) was added Et₃N (308μL, 2.2 mmol). The solution was cooled to 0° C. and methanesulfonylchloride (95 μL, 1.2 mmol) was added slowly over a period of 5 minutes.After 20 minutes of stirring at this temperature, LCMS indicated thatthe desired product had been formed. The solution was washed withice-cold water (5 mL), ice-cold 1N HCl (5 mL), NaHCO₃ (5 mL), andsaturated aqueous NaCl (5 mL). The organic layer was dried over Na₂SO₄,filtered and concentrated in vacuo to yield Compound 1 (602 mg).

To a solution of Compound 1 (602 mg, 1.1 mmol) in DMF (6 mL) was addedsodium cyanide (116 mg, 2.4 mmol) and 4-(dimethylamino)pyridine (13 mg,0.1 mmol), and the resulting mixture was heated to 50° C. and stirredovernight. EtOAc (20 mL) and water (20 mL) were added, and the layerswere separated. The organic layer was washed with water (3×20 mL), driedover Na₂SO₄, filtered, and concentrated in vacuo. The residue waspurified by column chromatography (0-60% EtOAc/hexanes) to yieldCompound 2 (421 mg).

To a solution of Compound 2 (84 mg, 0.2 mmol) in dioxane (4.3 mL) wasadded HCl (861 μL, 3.4 mmol). The resulting mixture was stirred at roomtemperature for 3 hours, after which time LCMS indicated that the BOCgroup had been removed. The solution was concentrated in vacuo. Theresidue was dissolved in DMF (2 mL) and DIPEA (90 μL, 0.5 mmol) andadded to a solution of 5-methyloxazole-2-carboxylic acid (26 mg, 0.2mmol), HATU (79 mg, 0.2 mmol) in DMF (4.3 mL), that had been stirred atroom temperature for 15 minutes. The resulting solution was stirred atroom temperature for 1 hour, until the reaction was complete. Thesolution was concentrated in vacuo and the residue purified by columnchromatography (0-60% EtOAc/hexanes) to yield Compound 3 (554 mg).

To a solution of Compound 3 (55 mg, 0.111 mmol) in EtOH (1.1 mL) wasadded NaOH (890 μl, 890 μmol). The solution was stirred at roomtemperature for 1 hour, then concentrated in vacuo and purified byreverse phase column chromatography. The desired fractions were combinedand lyophilized to yield Compound 4 (31 mg).

To a solution of Compound 4 (31 mg, 66 μmol) in EtOAc (1.5 mL) and AcOH(38 μL, 660 μmol) was added PdOH₂/C (4.6 mg, 33 μmol) and (BOC)₂O (15μL, 66 μmol). The resulting solution was sparged with hydrogen and thethen stirred at room temperature for 2 hours. The solution wasconcentrated in vacuo and the residue was purified by reverse phasecolumn chromatography to yield the title compound (1.7 mg; purity 100%)as a TFA salt. MS m/z [M+H]⁺ calc'd for C₂₄H₂₅ClFN₃O₄, 474.15; found474.2.

Example 24

Following the procedures described herein, and substituting theappropriate starting materials and reagents, these compounds wereprepared as a TFA salt:

MS m/z [M + H]⁺ Ex. R⁶ Formula calcd found 1

C₂₆H₂₉ClFN₃O₄ 502.18 502.2 2

C₂₂H₂₃ClFN₅O₃ 460.15 460.2

-   1.    (2R,4S)-2-(2-Aminoethyl)-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(4-isopropyloxazole-2-carbonyl)amino]pentanoic    acid-   2.    (2R,4S)-2-(2-Aminoethyl)-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoic    acid

Example 25:(2R,4R)-2-Acetylamino-5-(2′-fluorobiphenyl-4-yl)-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

(2R,4R)-2-Amino-5-(2′-fluorobiphenyl-4-yl)-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicacid (9 mg, 23 μmol) was dissolved in DCM (2 mL). Acetyl chloride (1.8μL, 25 μmol) and DIPEA (12 μL, 68 μmol) were added and the resultingmixture was stirred at room temperature for 15 minutes then concentratedin vacuo and the residue was dissolved in EtOH (2 mL). An aqueoussolution of 1N NaOH (227 μL, 227 μmol) was added and the mixture wasstirred at room temperature for 30 minutes then concentrated in vacuoand the residue was purified by reverse phase column chromatography toyield the title compound (5 mg; purity 98%). MS m/z [M+H]⁺ calc'd forC₂₂H₂₂FN₅O₄, 440.17; found 440.1.

Example 26:(2R,4R)-2-Acetylamino-5-biphenyl-4-yl-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

To a stirred solution of(2R,4R)-4-Amino-5-biphenyl-4-yl-2-hydroxypentanoic acid ethyl ester (200mg, 638 μmol), HATU (291 mg, 766 μmol), 3H-[1,2,3]triazole-4-carboxylicacid (87 mg, 766 μmol), and DMF (3 mL), was added DIPEA (357 μL, 2.0mmol), and the mixture was stirred at room temperature for 30 minutes. Asaturated aqueous NH₄Cl was added and the mixture was extracted withEtOAc. The organics were combined, dried over Na₂SO₄, and the solventwas evaporated. The crude residue was purified by normal phasechromatography (0-100% EtOAc/hexanes) to yield Compound 1 (76 mg).

Compound 1 (111 mg, 272 μmol) was dissolved in DCM (3 mL).Methanesulfonyl chloride (46.4 μL, 599 μmol) was added at 0° C.,followed by Et₃N (114 μL, 817 μmol). The mixture was stirred for 10minutes, and then concentrated and was purified by normal phasechromatography (0-100% EtOAc/hexanes) to yield Compound 2 (60 mg).

Compound 2 (60 mg, 123 μmol) in DMF (2 mL) was combined with sodiumazide (17.6 mg, 271 μmol), and the resulting mixture was stirredovernight. The solution was purified by normal phase chromatography(0-100% EtOAc/hexanes) to yield Compound 3 (54 mg).

Compound 3 (54 mg, 125 μmol) was combined with PdOH₂/C (17.5 mg, 25μmol) in MeOH. The flask was purged in vacuo (3×), then purged withnitrogen, then placed under hydrogen (1 atm) and stirred at roomtemperature for 30 minutes. The reaction was quenched with AcOH. Themixture was stirred for 10 minutes, filtered and concentrated in vacuoto yield Compound 4.

Compound 4 (10 mg, 25 μmol) was combined with DCM (2 mL), methylchloroformate (2.3 mg, 25 μmol) and Et₃N (3.4 μL, 25 μmol 1). Themixture was stirred for 10 minutes and the solvent evaporated to yieldCompound 5.

Compound 5 (11 mg, 24 μmol) was dissolved in THF (1 mL) and 1N NaOH (119μL, 119 μmol) and stirred at room temperature for 3 hours. To themixture was added AcOH and the solution was purified by reverse phasechromatography to yield the title compound (2 mg; purity 98%) as a TFAsalt. MS m/z [M+H]⁺ calc'd for C₂₂H₂₃N₅O₄, 422.18; found 422.

Example 27:(2R,4R)-5-Biphenyl-4-yl-2-propionylamino-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

Compound 4 was prepared as described herein.

Compound 4 (10 mg, 25 μmol) was combined with DCM (2 mL), propionylchloride (2.3 mg, 25 μmol) and Et₃N (3.4 μL, 25 μmol 1). The mixture wasstirred for 10 minutes and the solvent evaporated to yield Compound 5.

Compound 5 (11 mg, 24 μmol) was dissolved in THF (1 mL) and 10N NaOH(119 μL, 119 μmol) and stirred for 3 hours. To the mixture was addedAcOH and the solution was purified by reverse phase chromatography toyield the title compound (2 mg; purity 95%) as a TFA salt. MS m/z [M+H]⁺calc'd for C₂₃H₂₅N₅O₄, 436.19; found 436.

Example 28:(2S,4S)-2-(Acetylaminomethyl)-5-(5′-chloro-2′-fluoro-biphenyl-4-yl)-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

To a stirred solution of(2S,4S)-2-aminomethyl-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicacid (5 mg, 11 μmol), DCM (0.3 mL), and acetyl chloride (3.5 mg, 45μmol), was added Et₃N (9.4 μL, 67 μmol), and the mixture was stirred for5 minutes. The reaction was quenched with 1N NaOH (0.1 mL) and THF (0.5mL) and the mixture stirred for 10 minutes. The solvent was evaporatedand the residue was purified by reverse phase chromatography to yieldthe title compound (2 mg; purity 95%) as a TFA salt. MS m/z [M+H]⁺calc'd for C₂₃H₂₃ClFN₅O₄, 488.14; found 488.

Example 29:(2R,4R)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-4-[(3-ethyl-isoxazole-5-carbonyl)amino]-2-methoxycarbonylaminopentanoicAcid

3-Ethylisoxazole-5-carboxylic acid (5.5 mg, 39 μmol) and HATU (14.8 mg,39 μmol) were dissolved in DMF (3 mL) and stirred at room temperaturefor 15 minutes.(2R,4R)-4-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-methoxycarbonylamino-pentanoicacid ethyl ester (15 mg, 35 μmol) and DIPEA (19 μL, 106 μmol) wereadded, and the resulting mixture was stirred at room temperature for 15minutes (LC/MS showed reaction completion) then concentrated in vacuoand the residue was dissolved in EtOH (3 mL). An aqueous 1N NaOHsolution (355 μL, 355 μmol) was added, and the resulting mixture wasstirred at room temperature for 1 hour (LC/MS showed reactioncompletion) then concentrated in vacuo and the residue purified bypreparative HPLC to yield the title compound (3.7 mg; purity 100%). MSm/z [M+H]⁺ calc'd for C₂₅H₂₅ClFN₃O₆, 518.14; found 518.2.

Example 30

Following the procedures described herein, and substituting theappropriate starting materials and reagents, these compounds wereprepared, either as the parent compound or as a TFA salt:

MS m/z [M + H]⁺ Ex. R⁶ Formula calcd found 1

C₂₂H₂₁ClFN₅O₅ 490.12 490.0 2

C₂₅H₂₄ClFN₄O₆ 531.14 531.2 3

C₂₃H₂₁ClFN₃O₆ 490.11 490.2 4

C₂₄H₂₃ClFN₃O₆ 504.13 504 5

C₂₆H₂₅ClFN₃O₆ 530.14 530.2 6

C₂₅H₂₅ClFN₃O₆ 518. 14 518.2 7

C₂₅H₂₅ClFN₃O₇ 534.14 534.2 8

C₂₆H₂₇ClFN₃O₇ 548.15 548.2 9

C₂₂H₂₀ClFN₄O₇ 507.10 507.2 10

C₂₃H₂₁ClFN₃O₇ 506.11 506.2 11

C₂₃H₂₁ClFN₃O₇ 506.11 506.2 12

C₂₅H₂₂Cl₂FN₃O₅ 534.09 534.2

-   1.    (2R,4R)-5-(5′-Chloro-2′-fluoro-biphenyl-4-yl)-2-methoxycarbonylamino-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoic    acid-   2.    (2R,4R)-4-[(5-Acetyl-2H-pyrazole-3-carbonyl)-amino]-5-(5′-chloro-2′-fluoro-biphenyl-4-yl)-2-methoxycarbonylaminopentanoic    acid-   3.    (2R,4R)-5-(5′-Chloro-2′-fluoro-biphenyl-4-yl)-2-methoxycarbonylamino-4-[(oxazole-2-carbonyl)amino]pentanoic    acid-   4.    (2R,4R)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-methoxycarbonylamino-4-[(5-methyloxazole-2-carbonyl)amino]pentanoic    acid-   5.    (2R,4R)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-4-[(2-cyclopropyl-oxazole-4-carbonyl)amino]-2-methoxycarbonylaminopentanoic    acid-   6.    (2R,4R)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-4-[(2-ethyl-oxazole-4-carbonyl)amino]-2-methoxycarbonylaminopentanoic    acid-   7.    (2R,4R)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-4-[(2-ethoxy-oxazole-4-carbonyl)amino]-2-methoxycarbonylaminopentanoic    acid-   8.    (2R,4R)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-4-[(5-ethoxy-4-methyl-oxazole-2-carbonyl)amino]-2-methoxycarbonylaminopentanoic    acid-   9.    (2R,4R)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-methoxycarbonylamino-4-[(5-oxo-4,5-dihydro-[1,2,4]oxadiazole-3-carbonyl)amino]pentanoic    acid-   10.    (2R,4R)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-methoxycarbonylamino-4-[(2-oxo-2,3-dihydro-oxazole-5-carbonyl)amino]pentanoic    acid-   11.    (2R,4R)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-methoxycarbonylamino-4-[(2-oxo-2,3-dihydro-oxazole-4-carbonyl)amino]pentanoic    acid-   12.    (2R,4R)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-4-[(5-chloro-pyridine-2-carbonyl)-amino]-2-methoxycarbonylaminopentanoic    acid

Example 31:(2R,4R)-5-Biphenyl-4-yl-2-methoxycarbonylamino-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

Compound 4 was prepared as described herein.

To a stirred solution of Compound 4 (10 mg, 25 μmol) in DCM (2 mL), wasadded methyl chloroformate (2.3 mg, 25 μmol) and Et₃N (3.4 μL, 25 μmol).The mixture was stirred for 10 minutes and the solvent evaporated toyield Compound 5.

A solution of Compound 5 (11 mg, 24 μmol) in THF (1 mL) and 1N NaOH (119μL, 119 μmol) was stirred for 3 hours. To the mixture was added AcOH andthe solution was purified by reverse phase chromatography to yield thetitle compound (2 mg; purity 95%) as a TFA salt. MS m/z [M+H]⁺ calc'dfor C₂₂H₂₃N₅O₅, 438.17; found 438.

Example 32:(2R,4R)-2-(2-Aminoacetylamino)-5-(2′-fluorobiphenyl-4-yl)-4-[(1H-[1.2.3]triazole-4-carbonyl)amino]pentanoicAcid

n-BOC-Glycine (9.7 mg, 55 μmol) and HATU (21.1 mg, 55 μmol) weredissolved in DMF (2 mL) and stirred for 15 minutes at room temperature.(2R,4R)-2-Amino-5-(2′-fluorobiphenyl-4-yl)-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicacid (20 mg, 50 μmol) and DIPEA (22 μL, 126 μmol) were added and theresulting mixture was stirred at room temperature for 15 minutes, atwhich time LCMS indicated the mass of the desired compound. The mixturewas concentrated in vacuo and the residue was dissolved in EtOH (2 mL).An aqueous solution of 1N NaOH (503 μl, 503 μmol) was added and theresulting mixture was stirred at room temperature for 30 minutes (LC/MSshowed the mass of the desired product) then concentrated in vacuo toyield Compound 1, which was used in the next step without purification.

Compound 1 (14 mg, 25 μmol) was dissolved in MeCN (2 mL). A solution of4N HCl in dioxane (63 μL, 252 μmol) was added and the mixture wasstirred at room temperature for 10 minutes, at which time LCMS indicatedthe mass of the desired compound. The mixture was concentrated in vacuoand the residue was purified by reverse phase column chromatography toyield the title compound (3 mg; purity 96%) as a TFA salt. MS m/z [M+H]⁺calc'd for C₂₂H₂₃FN₆O₄, 455.18; found 455.

Example 33:(2R,4R)-2-(2-Aminoacetylamino)-5-(5′-chloro-2′-fluoro-biphenyl-4-yl)-4-[(1H-[1.2.3]triazole-4-carbonyl)amino]pentanoicAcid

n-BOC-Glycine (3.3 mg, 19 μmol) and HATU (7.1 mg, 19 μmol) weredissolved in DMF (2 mL) and stirred for 15 minutes at room temperature.(2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicacid (7.3 mg, 17 μmol) and DIPEA (8.9 μL, 51 μmol) were added and theresulting mixture was stirred at room temperature for 15 minutes, atwhich time LCMS indicated the mass of the desired compound. The mixturewas concentrated in vacuo to yield Compound 1, which was used in thenext step without purification.

Compound 1 (10 mg, 17 μmol) was dissolved in MeCN (2 mL). A solution of4N HCl in dioxane (4.2 μL, 17 μmol) was added and the mixture wasstirred at room temperature for 15 minutes, at which time LCMS indicatedthe mass of the desired 5 compound. The mixture was concentrated invacuo and the residue was purified by reverse phase columnchromatography to yield the title compound (2.5 mg; purity 98%) as a TFAsalt. MS m/z [M+H]⁺ calc'd for C₂₂H₂₂ClFN₆O₄, 489.14; found 489.

Example 34

Following the procedures described herein, and substituting theappropriate starting materials and reagents, this compound was preparedas a TFA salt:

MS m/z [M + H]⁺ Ex. R⁶ Formula calcd found 1

C₂₆H₂₈ClFN₄O₅ 531.17 531.2

-   1.    (2R,4R)-2-(2-Aminoacetylamino)-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(4-isopropyloxazole-2-carbonyl)amino]pentanoic    acid

Example 35:(2R,4R)-2-(2-Amino-2-methylpropionylamino)-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(4-isopropyloxazole-2-carbonyl)amino]pentanoicAcid

2-t-Butoxycarbonylamino-2-methylpropionic acid (4.5 mg, 22 μmol) andHATU (8.4 mg, 22 μmol) were dissolved in DMF (2 mL) and stirred for 15min at room temperature.(2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(4-isopropyloxazole-2-carbonyl)amino]pentanoicacid (10 mg, 21 μmol) and DIPEA (11 μL, 63 μmol) were added, and theresulting mixture was stirred at room temperature for 15 minutes, atwhich time LCMS indicated the mass of the desired compound. The mixturewas concentrated in vacuo and the residue was dissolved in MeCN (2 mL).An excess of a solution of 4N HCl in dioxane was added, and theresulting mixture was stirred at room temperature for 15 minutes, atwhich time LCMS indicated the mass of the desired compound. The mixturewas concentrated in vacuo and the residue was purified by preparativeHPLC to yield the title compound (2.1 mg; purity 96%) as a TFA salt. MSm/z [M+H]⁺ calc'd for C₂₈H₃₂ClFN₄O₅, 559.20; found 559.2.

Example 36:(2R,4R)-2-((S)-2-Aminopropionylamino)-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(4-isopropyloxazole-2-carbonyl)amino]pentanoicAcid (compound 36-1) and(2R,4R)-2-((R)-2-Aminopropionylamino)-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(4-isopropy-oxazole-2-carbonyl)-amino]pentanoicAcid (compound 36-2)

(S)-2-t-Butoxycarbonylaminopropionic acid (4.2 mg, 22 μmol) and HATU(8.4 mg, 22 μmol) were dissolved in DMF (2 mL) and stirred for 15 min atroom temperature.(2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(4-isopropyloxazole-2-carbonyl)amino]pentanoicacid (10 mg, 21 μmol) and DIPEA (11 μL, 63 μmol) were added, and theresulting mixture was stirred at room temperature for 15 minutes, atwhich time LCMS indicated the mass of the desired compound. The mixturewas concentrated in vacuo and the residue was dissolved in MeCN (2 mL).An excess of a solution of 4N HCl in dioxane was added, and theresulting mixture was stirred at room temperature for 15 minutes, atwhich time LCMS indicated the mass of the desired compound. The mixturewas concentrated in vacuo and the residue was purified by preparativeHPLC to yield the title Compound 36-1 (2.4 mg; purity 100%) as a TFAsalt. MS m/z [M+H]⁺ calc'd for C₂₇H₃₀ClFN₄O₅, 545.19; found 545.2.

This procedure was repeated using (R)-2-t-butoxycarbonylaminopropionicacid (4.5 mg, 22 μmol) to yield the title Compound 36-2 (2.2 mg; purity100%) as a TFA salt. MS m/z [M+H]⁺ calc'd for C₂₇H₃₀ClFN₄O₅, 545.19;found 545.2.

Example 37

Following the procedures described herein, and substituting theappropriate starting materials and reagents, this compound was preparedas a TFA salt:

MS m/z [M + H]⁺ Ex. R⁶ Formula calcd found 1

C₂₃H₂₄ClFN₆O₄ 503.15 503.2

-   1.    (2R,4R)-2-((S)-2-Aminopropionylamino)-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoic    acid

Example 38:(2R,4R)-2-((R)-2-Amino-3-methylbutyrylamino)-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(4-isopropyloxazole-2-carbonyl)amino]pentanoicAcid (compound 38-1) and(2R,4R)-2-((S)-2-Amino-3-methylbutyrylamino)-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(4-isopropyloxazole-2-carbonyl)-amino]pentanoicAcid (compound 38-2)

(R)-2-t-Butoxycarbonylamino-3-methylbutyric acid (4.8 mg, 22 μmol) andHATU (8.4 mg, 22 μmol) were dissolved in DMF (2 mL) and stirred for 15min at room temperature.(2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(4-isopropyloxazole-2-carbonyl)amino]pentanoicacid (10 mg, 21 μmol) and DIPEA (11 μL, 63 μmol) were added, and theresulting mixture was stirred at room temperature for 15 minutes, atwhich time LCMS indicated the mass of the desired compound. The mixturewas concentrated in vacuo and the residue was dissolved in MeCN (2 mL).An excess of a solution of 4N HCl in dioxane was added, and theresulting mixture was stirred at room temperature for 15 minutes, atwhich time LCMS indicated the mass of the desired compound. The mixturewas concentrated in vacuo and the residue was purified by preparativeHPLC to yield the title Compound 38-1 (1.7 mg; purity 92%) as a TFAsalt. MS m/z [M+H]⁺ calc'd for C₂₉H₃₄ClFN₄O₅, 573.22; found 573.2.

This procedure was repeated using(S)-2-t-butoxycarbonylamino-3-methylbutyric acid (4.8 mg, 22 μmol) toyield the title Compound 38-2 (1.1 mg; purity 81%) as a TFA salt. MS m/z[M+H]⁺ calc'd for C₂₉H₃₄ClFN₄O₅, 573.22; found 573.2. MS m/z [M+H]⁺calc'd for C₂₇H₃₀ClFN₄O₅, 545.19; found 545.2.

Example 39

Following the procedures described herein, and substituting theappropriate starting materials and reagents, this compound was preparedas a TFA salt:

MS m/z [M + H]⁺ Ex. R⁶ Formula calcd found 1

C₂₅H₂₈ClFN₆O₄ 531.18 531.2

-   1.    (2R,4R)-2-((S)-2-Amino-3-methylbutyrylamino)-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoic    acid

Example 40:(2R,4R)-2-(4-Aminobutyrylamino)-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

1H-1,2,3-triazole-4-carboxylic acid (135 mg, 1.2 mmol) and HATU (453 mg,1.2 mmol) were dissolved in DMF (4 mL) and stirred for 15 minutes atroom temperature.(2R,4R)-4-Amino-2-azido-5-(5′-chloro-2′-fluorobiphenyl-4-yl)pentanoicacid ethyl ester (423 mg, 1.2 mmol) and DIPEA (567 μL, 3.3 mmol) wereadded, and the mixture was stirred at room temperature for 15 minutes,at which time LCMS indicated the mass of the desired compound. Themixture was concentrated in vacuo and the crude residue was purified bynormal phase column chromatography (20-100% EtOAc/hexanes) to yieldCompound 1 (324 mg).

Compound 1 (203 mg, 443 μmol) and palladium hydroxide (12.5 mg, 89 μmol)were stirred in dry MeOH (3 mL) and AcOH (3 mL). The hydrogen wasremoved in vacuo and the flask was purged with nitrogen and the mixturestirred at room temperature for 1 hour. LC/MS showed the desired mass.The mixture was filtered and the solution was purified by preparativeHPLC to yield Compound 2 (105 mg).

4-t-Butoxycarbonylaminobutyric acid (6.4 mg, 31 μmol) and HATU (10.8 mg,28 μmol) were dissolved in DMF (3 mL) and stirred for 15 minutes at roomtemperature. Compound 2 (12.3 mg, 28 μmol) and DIPEA (15 μL, 85 μmol)were added, and the mixture was stirred at room temperature for 15minutes (LC/MS showed the desired product) then concentrated in vacuoand the residue was dissolved in MeCN (2 mL). A solution of 4N HCl indioxane (107 mL, 427 μmol) was added, and the mixture was stirred for 15minutes at room temperature. LC/MS showed the desired mass. The solventwas removed in vacuo and the residue was purified by preparative HPLC toyield the title compound (8 mg; purity 100%) as a TFA salt. MS m/z[M+H]⁺ calc'd for C₂₄H₂₆ClFN₆O₄, 517.17; found 517.2.

Example 41:(2R,4R)-2-(3-Aminopropionylamino)-5-(5′-chloro-2′-fluoro-biphenyl-4-yl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

Compound 2 was prepared as described herein.

3-t-Butoxycarbonylaminopropionic acid (5.9 mg, 31 μmol) and HATU (10.8mg, 28 μmol) were dissolved in DMF (3 mL) and stirred for 15 minutes atroom temperature. Compound 2 (12.3 mg, 28 μmol) and DIPEA (15 μL, 85μmol) were added, and the mixture was stirred at room temperature for 15minutes (LC/MS showed the desired product) then concentrated in vacuoand the residue was dissolved in MeCN (2 mL). A solution of 4N HCl indioxane (107 mL, 427 μmol) was added, and the mixture was stirred for 15minutes at room temperature. LC/MS showed the desired mass. The solventwas removed in vacuo and the residue was purified by preparative HPLC toyield the title compound (8.2 mg; purity 100%) as a TFA salt. MS m/z[M+H]⁺ calc'd for C₂₃H₂₄ClFN₆O₄, 503.15; found 503.2.

Example 42:(2R,4R)-2-((R)-2-Amino-3-hydroxypropionylamino)-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(4-isopropyloxazole-2-carbonyl)-amino]pentanoicAcid (compound 42-1) and(2R,4R)-2-((S)-2-Amino-3-hydroxypropionylamino)-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(4-isopropyloxazole-2-carbonyl)amino]pentanoicAcid (compound 42-2)

(R)-2-t-Butoxycarbonylamino-3-hydroxypropionic acid (4.5 mg, 22 μmol)and HATU (8.4 mg, 22 μmol) were dissolved in DMF (2 mL) and stirred atroom temperature for 15 minutes.(2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(4-isopropyloxazole-2-carbonyl)amino]pentanoicacid (10 mg, 21 μmol) and DIPEA (11 μL, 63 μmol) were added, and theresulting mixture was stirred at room temperature for 15 minutes, atwhich time LCMS indicated the mass of the desired compound. The mixturewas concentrated in vacuo and the residue was dissolved in MeCN (2 mL).An excess of a solution of 4N HCl in dioxane was added, and theresulting mixture was stirred at room temperature for 15 minutes, atwhich time LCMS indicated the mass of the desired compound. The mixturewas concentrated in vacuo and the residue was purified by preparativeHPLC to yield the title Compound 42-1 (1 mg; purity 100%) as a TFA salt.MS m/z [M+H]⁺ calc'd for C₂₇H₃₀ClFN₄O₆, 561.18; found 561.2.

This procedure was repeated using(S)-2-t-butoxycarbonylamino-3-hydroxypropionic acid (4.5 mg, 22 μmol) toyield the title Compound 42-2 (1.3 mg; purity 100%) as a TFA salt. MSm/z [M+H]⁺ calc'd for C₂₇H₃₀ClFN₄O₆, 561.18; found 561.2.

Example 43:(2S,4S)-2-[(2-Aminoacetylamino)methyl]-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(5-methyloxazole-2-carbonyl)amino]pentanoicAcid

(2S,4S)-4-t-Butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-hydroxymethylpentanoicacid ethyl ester (1.65 g, 3.4 mmol) was dissolved in MeCN (6 mL) and 4NHCl in dioxane (3 mL), and stirred for 10 minutes. The mixture wasconcentrated under reduced pressure to yield Compound 1 (1.26 g) as andHCl salt, which was used without further purification.

5-methyloxazole-2-carboxylic acid (422 mg, 3.3 mmol) was combined withHATU (1261 mg, 3.3 mmol) in DMF (3 mL) and stirred for 10 minutes. DIPEA(869 μL) was added and the mixture was stirred for 1 minute. Compound 1(1.26 g, 3.3 mmol) was dissolved in DMF (1 mL) and DIPEA (869 μL) wasadded, followed by addition of the activated5-methyloxazole-2-carboxylic acid solution. The resulting mixture wasstirred for 30 minutes and concentrated in vacuo to yield Compound 2,which was used without further purification.

Compound 2 (1.6 g, 3.3 mmol) was dissolved in THF (10 mL) and 5N NaOH(3.3 mL, 16.6 mmol) and stirred for 2 hours at 50° C. AcOH was added andthe solution was 5 purified by reverse phase chromatography to yieldCompound 3 (589 mg).

To a stirred solution of Compound 3 (390 mg, 846 μmol) in DCM (10 mL),was added methanesulfonyl chloride (79 μL, 1.0 mmol) and Et₃N (259 μL,1.9 mmol). The resulting mixture was stirred for 5 minutes andconcentrated in vacuo to yield Compound 4, which was used withoutfurther purification.

Compound 4 (200 mg, 371 μmol) in DMF (1 mL) was combined with sodiumazide (72.4 mg, 1.1 mmol) and the mixture was stirred at 50° C. for 2hours. The reaction was quenched with water and extracted with EtOAc.The organic layer was washed with water (3×) and then concentrated invacuo. The residue was then purified by normal phase chromatography(0-100% EtOAc/hexanes) to yield Compound 5.

Compound 5 (100 mg, 206 μmol) was combined with palladium on carbon (11mg, 21 μmol), AcOH (0.3 mL) and EtOAc (1 mL). The reaction flask waspurged with nitrogen and hydrogen (1 atm) added. The mixture was stirredfor 2 hours. Hydrogen was removed in vacuo and nitrogen added. To themixture was added AcOH (2 mL), the mixture was filtered and the solutionwas purified by reverse phase chromatography to yield Compound 6 (40mg).

t-Butoxycarbonylamino acetic acid (3.1 mg, 17 μmol) was combined withHATU (6.6 mg, 17 μmol), DMF (0.5 mL) and DIPEA (9.1 μL, 52 μmol), andstirred for 5 minutes. This was then added to a solution of Compound 6(8.0 mg, 17 μmol) in DMF (0.5 mL) and DIPEA (3 eq.). The mixture wasstirred for 10 minutes and the reaction was quenched with a saturatedNaHCO₃ solution (1 mL) and EtOAc (3 mL). The organic layer was extractedand dried over MgSO₄, filtered and concentrated under pressure to yieldCompound 7.

Compound 7 (8 mg, 13 μmol) was dissolved in MeCN (0.5 mL) and dry 4N HClin dioxane (0.5 mL). The mixture was stirred for 10 minutes and thesolvent removed under reduced pressure. The residue was then purified byreverse phase chromatography to yield the title compound (2.5 mg; purity95%) as a TFA salt. MS m/z [M+H]⁺ calc'd for C₂₅H₂₆ClFN₄O₅, 517.16;found 517.

Example 44

Following the procedures described herein, and substituting theappropriate starting materials and reagents, these compounds wereprepared as a TFA salt:

MS m/z [M + H]⁺ Ex. R¹ R⁶ Formula calcd found 1 H

C₂₃H₂₄ClFN₆O₄ 503.15 502 2 —CH₂CH₃

C₂₅H₂₈ClFN₆O₄ 531.18 531

-   1.    (2S,4S)-2-[(2-Aminoacetylamino)methyl]-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoic    acid-   2.    (2S,4S)-2-[(2-Aminoacetylamino)methyl]-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoic    acid ethyl ester

Example 45(2S,4S)-2-[(2-Amino-2-methylpropionylamino)methyl]-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(5-methyloxazole-2-carbonyl)-amino]pentanoicAcid

Compound 6 was prepared as described herein.

2-t-Butoxycarbonylamino-2-methylpropionic acid (3.5 mg, 17 μmol) wascombined with HATU (6.6 mg, 17 μmol), DMF (0.5 mL) and DIPEA (9.1 μL, 52μmol), and stirred for 5 minutes. This was then added to a solution ofCompound 6 (8.0 mg, 17 μmol) in DMF (0.5 mL) and DIPEA (3 eq.). Themixture was stirred for 10 minutes and the reaction was quenched with asaturated aqueous NaHCO₃ solution (1 mL) and EtOAc (3 mL). The organiclayer was separated and dried over MgSO₄ followed by evaporation underpressure to yield Compound 7.

Compound 7 (8.4 mg, 13 μmol) was dissolved in MeCN (0.5 mL) and dry 4NHCl in dioxane (0.5 mL). The mixture was stirred for 10 minutes and thesolvent removed under reduced pressure. The residue was then purified(reverse phase chromatography) to yield the title compound (2 mg; purity95%) as a TFA salt. MS m/z [M+H]⁺ calc'd for C₂₇H₃₀ClFN₄O₅, 545.19;found 545.

Example 46:(2R,4R)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-((S)-2-methoxycarbonylamino-3-methylbutyrylamino)-4-[(1H-[1,23]triazole-4-carbonyl)amino]pentanoicAcid

(2S)-2-[(methoxycarbonyl)amino]-3-methylbutanoic acid (6.7 mg, 38 μmol)and HATU (13.9 mg, 36 μmol) were dissolved in DMF (4 mL) and stirred atroom temperature for 15 minutes.(2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicacid (15 mg, 35 μmol) and DIPEA (15 μL, 87 μmol) were then added, andthe resulting mixture was stirred at room temperature for 15 minutes.LC/MS showed reaction completion (2 isomers were observed). The solutionwas concentrated in vacuo and the residue was purified by preparativeHPLC to yield the title compound (6 mg; purity 100%) as a white powderTFA salt. The 1:1 ratio of isomers were not isolated. MS m/z [M+H]⁺calc'd for C₂₇H₃₀ClFN₆O₆, 589.19; found 589.19.

Example 47:(2R,4R)-5-Biphenyl-4-yl-2-methanesulfonylamino-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

Compound 4 was prepared as described herein.

Compound 4 (10 mg, 25 μmol) was combined with DCM (2 mL),methanesulfonyl chloride (2.8 mg, 25 μmol) and Et₃N (3.4 μL, 25 μmol 1).The mixture was stirred for 10 minutes and the solvent evaporated toyield Compound 5.

Compound 5 (11.5 mg, 24 μmol) was dissolved in THF (1 mL) and 1N NaOH(119 μL, 119 μmol) and stirred for 3 hours. The reaction was quenchedwith AcOH and the solution was purified by reverse phase chromatographyto yield the title compound (2 mg; purity 95%) as a TFA salt. MS m/z[M+H]⁺ calc'd for C₂₁H₂₃N₅O₅S, 458.14; found 458.

Example 48:(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-[(2-hydroxyethylamino)methyl]-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid (isomer a) and (isomer b) and(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-[(2-hydroxyethylamino)methyl]-4-[(3H-[1.2.3]triazole-4-carbonyl)-amino]pentanoicAcid Ethyl Ester (compound c)

(2S,4S)-4-t-Butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-methanesulfonyloxymethylpentanoicacid ethyl ester (28 mg, 50 μmol) was combined with EtOH (2 mL),followed by Na₂CO₃ (16.0 mg, 151 μmol) and 2-aminoethanol (9.2 mg, 151μmol) and stirred at 70° C. overnight. EtOAc and water were added, theorganic layer was separated and concentrated under reduced pressure toyield Compound 1.

Compound 1 (25.7 mg, 49 μmol) was dissolved in MeCN (0.5 mL) and dry 4NHCl in dioxane (0.1 mL). The mixture was stirred for 10 minutes and wasthen concentrated 5 under reduced pressure. The residue was purified byreverse phase chromatography to yield Compound 2 (8 mg).

3H-1,2,3-triazole-5-carboxylic acid (1.1 mg, 10.0 μmol) was combinedwith HATU (3.0 mg, 7.8 μmol) in DMF (0.5 mL) and stirred for 10 minutes;DIPEA (1.0 eq.) was added and the mixture was stirred for 1 minute.Compound 2 (4.7 mg, 11 μmol) was dissolved in DMF (1 mL) and DIPEA (5.8μL, 33 mmol) was added, followed by addition of the activated acidsolution. The mixture was stirred for 30 minutes to yield crude Compound3.

To the crude solution of Compound 3 (5.7 mg, 11 μmol) was added 1N LiOH(55.1 μL, 55 μmol) and THF (0.5 mL). The mixture was stirred for 40minutes and AcOH (1 mL) was added. The solution was purified by reversephase chromatography to yield isomer a (MS m/z [M+H]⁺ calc'd forC₂₃H₂₅ClFN₅O₄, 490.16; found 490) and isomer b (MS m/z [M+H]⁺ calc'd forC₂₃H₂₅ClFN₅O₄, 490.16; found 490).

(2S,4S)-2-(4-Bromobenzenesulfonyloxymethyl)-4-t-butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)pentanoicacid ethyl ester (100 mg, 143 μmol) was dissolved in EtOH (3 mL),followed by addition of Na₂CO₃ (152 mg, 1.4 mmol) and 2-amino-ethanol(44 mg, 715 μmol). The resulting mixture was stirred for 2 days at 70°C., at which time LCMS indicated the mass of the desired compound. Themixture was concentrated under reduced pressure and the crude residuewas dissolved in AcOH (4 mL) and H₂O (1 mL) and purified by reversephase chromatography (10-80% MeCN/H₂O gradient) to yield Compound 4 (20mg).

Compound 4 (26 mg, 50 μmol) was dissolved in MeCN (1 mL) and dry 4N HClin dioxane (0.5 mL). The mixture was stirred for 10 minutes and thenconcentrated under reduced pressure to yield Compound 5 as an HCl salt,which was used in the next step without purification.

1H-1,2,3-triazole-5-carboxylic acid (3.4 mg, 30 μmol) was combined withHATU (11 mg, 30 μmol) in DMF (0.3 mL) and stirred at room temperaturefor 10 minutes; DIPEA (1 eq.) was added and the mixture was stirred for1 minute. Compound 5 (9 mg, 30 μmol) was dissolved in DMF (0.5 mL) andDIPEA (5.2 μL, 30 μmol) was added, followed by addition of the activatedacid solution. The mixture was stirred at room temperature for 30minutes, after which time LCMS indicated desired product formation. Halfof the crude product was purified using reverse phase chromatography toyield the title compound c as a TFA salt (1 mg). MS m/z [M+H]⁺ calc'dfor C₂₅H₂₉ClFN₅O₄, 518.19; found 518.

Example 49:(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-[(2-methoxyethylamino)-methyl]-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid (isomer a) and (isomer b) and(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-[(2-methoxyethylamino)methyl]-4-[(3H-[1,2,3]triazole-4-carbonyl)-amino]pentanoicAcid Ethyl Ester (compound c)

(2S,4S)-4-t-Butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-methanesulfonyloxymethylpentanoicacid ethyl ester (28 mg, 50 μmol) was combined with EtOH (2 mL),followed by Na₂CO₃ (16.0 mg, 151 μmol) and 2-methoxyethylamine (11.3 mg,151 μmol) and stirred at room temperature overnight. EtOAc and water wasadded, the organic layer was separated and concentrated under reducedpressure to yield Compound 1.

Compound 1 (26.4 mg, 49 mol) was dissolved in MeCN (0.5 mL) and dry 4NHCl in dioxane (0.1 mL). The mixture was stirred for 10 minutes and wasthen concentrated under reduced pressure. The residue was purified byreverse phase chromatography to yield Compound 2 (10 mg).

3H-1,2,3-triazole-5-carboxylic acid (1.1 mg, 10.0 μmol) was combinedwith HATU (3.0 mg, 7.8 μmol) in DMF (0.5 mL) and stirred for 10 minutes;DIPEA (1.0 eq.) was added and the mixture was stirred for 1 minute.Compound 2 (4.9 mg, 11 μmol) was dissolved in DMF (1 mL) and DIPEA (5.8μL, 33 mmol) was added, followed by addition of the activate acidsolution. The mixture was stirred for 30 minutes to yield Compound 3.

To a solution of crude Compound 3 (5.9 mg, 11 μmol) was added 1N LiOH(55.1 μL, 55 μmol) and THF (0.5 mL). The mixture was stirred for 40minutes and AcOH (1.0 mL) was added. The solution was purified byreverse phase chromatography to yield isomer a (MS m/z [M+H]⁺ calc'd forC₂₄H₂₇ClFN₅O₄, 504.17; found 504) and isomer b (MS m/z [M+H]⁺ calc'd forC₂₄H₂₇ClFN₅O₄, 504.17; found 504).

1H-1,2,3-triazole-4-carboxylic acid (2.6 mg, 23 μmol) and HATU (9.6 mg,25 μmol) were combined in DMF (3.0 mL) and stirred at room temperaturefor 15 minutes.(2S,4S)-4-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-[(2-methoxyethylamino)methyl]-pentanoicacid ethyl ester (10 mg, 23 μmol) and DIPEA (12 μL, 69 μmol) were addedand the resulting solution was stirred at room temperature for 15minutes, after which time LCMS indicated desired product formation. Thesolvent was removed in vacuo and the crude residue was purified byreverse phase chromatography to yield the title compound c as a TFA salt(1.2 mg). MS m/z [M+H]⁺ calc'd for C₂₆H₃₁ClFN₅O₄, 532.21; found 532.

Example 50:(2S,4S)-5-Biphenyl-4-yl-2-cyanomethyl-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

(2S,4S)-4-Amino-5-biphenyl-4-yl-2-cyanomethylpentanoic acid ethyl ester(70 mg, 199 μmol) was combined with DMF (1 mL), HATU (76 mg, 199 μmol),DIPEA (104 μL, 596 μmol), and 3H-[1,2,3]triazole-4-carboxylic acid (22mg, 199 μmol) and the mixture was stirred at room temperature for 20minutes. The solvent was evaporated and the crude mixture was purifiedby normal phase chromatography (0-100% EtOAc/hexanes) to yield Compound1 (60 mg).

Compound 1 (28.9 mg, 67 μmol) was dissolved in THF (1 mL) and 1N NaOH(268 μL, 268 μmol) and stirred at room temperature for 1 hour. Themixture was acidified with AcOH (1 mL) and purified by preparative HPLCto yield the title compound (19 mg; purity 90%) as a TFA salt. MS m/z[M+H]⁺ calc'd for C₂₂H₂₁N₅O₃, 404.16; found 404.

Example 51:(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-cyanomethyl-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

(2S,4S)-4-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-cyanomethylpentanoicacid ethyl ester (55 mg, 141 μmol) was combined with3H-[1,2,3]triazole-4-carboxylic acid (19.2 mg, 170 μmol), HATU (64.5 mg,170 μmol) and DIPEA (79 μL, 453 μmol) in DMF (2 mL) and was stirred atroom temperature for 30 minutes then concentrated in vacuo and the cruderesidue was purified by normal phase chromatography (0-100%EtOAc/hexanes) to yield Compound 1 55 mg).

Compound 1 (48.4 mg, 0.1 mmol) was dissolved in THF (2 mL) and 2N NaOH(250 μL, 0.5 mmol) and stirred for 1 hour, then concentrated underreduced pressure. The crude residue was dissolved in AcOH (2 mL) waspurified by reverse phase chromatography to yield the title compound (15mg; purity 95%) as a TFA salt. MS m/z [M+H]⁺ calc'd for C₂₂H₁₉ClFN₅O₃,456.12; found 455.

Example 52

Following the procedures described herein, and substituting theappropriate starting materials and reagents, these compounds wereprepared as the parent compound:

MS m/z [M + H]⁺ Ex. R⁶ Formula calcd found 1

C₂₄H₂₁ClFN₃O₃S 486.1 486.2 2

C₂₄H₂₁ClFN₃O₃S 486.1 486.2 3

C₂₃H₁₉ClFN₃O₃S 472.08 472.2

-   1.    (S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-cyanomethyl-4-[(3-methylisothiazole-5-carbonyl)amino]pentanoic    acid (diastereomer 1)-   2.    (S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-cyanomethyl-4-[(3-methylisothiazole-5-carbonyl)amino]pentanoic    acid (diastereomer 2)-   3.    (2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-cyanomethyl-4-[(isothiazole-4-carbonyl)amino]pentanoic    acid

Example 53:(2S,4S)-5-Biphenyl-4-yl-2-carbamoylmethyl-4-[(3H-[1.2.3]triazole-4-carbonyl)amino]pentanoicAcid

(2S,4S)-5-Biphenyl-4-yl-2-cyanomethyl-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicacid (5 mg, 12 μmol) was combined with DMSO (0.5 mL), H₂O₂(54.4 μL, 533μmol) and K₂CO₃ (15.4 mg, 112 μmol), and stirred overnight. The reactionwas quenched with 1 drop of concentrated HCl. AcOH was added and themixture was purified by reverse phase chromatography to yield the titlecompound (2 mg; purity 95%) as a TFA salt. MS m/z [M+H]⁺ calc'd forC₂₂H₂₃N₅O₄, 422.18; found 422.

Example 54:(2R,4S)-2-Carbamoylmethyl-5-(3′-fluorobiphenyl-4-yl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

(2R,4S)-4-t-butoxycarbonylamino-5-(3′-fluorobiphenyl-4-yl)-2-hydroxymethylpentanoicacid ethyl ester (985 mg, 2.2 mmol) was dissolved in MeCN (10 mL) and 4NHCl in dioxane (5 mL) and stirred for 15 minutes, then concentratedunder reduced pressure to yield Compound 1.

Compound 1 (500 mg, 1.4 mmol) was combined with HATU (656 mg, 1.7 mmol),3H-[1,2,3]triazole-4-carboxylic acid (195 mg, 1.7 mmol) and DMF (3 mL).DIPEA (803 μL, 4.6 mmol) was added and the mixture was stirred for 30minutes. Saturated aqueous 5 NH₄Cl (10 mL) and EtOAc (40 mL) were added.The organic layer was separated and dried over MgSO₄. The solvent wasevaporated and the residue purified by normal phase chromatography(0-100% EtOAc/hexanes) to yield Compound 2 (650 mg).

Compound 2 (650 mg, 1.5 mmol) was dissolved in DCM (3 mL).Methanesulfonyl chloride (173 μL, 2.2 mmol) was added at 0° C., followedby the slow addition of Et₃N (425 μL, 3.0 mmol). The mixture was stirredfor 10 minutes and the solution was purified by normal phasechromatography (0-100% EtOAc/hexanes) to yield Compound 3 (690 mg).

Compound 3 (390 mg, 752 μmol) was dissolved in DMF (2 mL). Sodiumcyanide (47.9 mg, 978 μmol) and DMAP (3 mg) was added and the mixturewas stirred at 50° C. overnight. EtOAc (5 mL) and water (2 mL) wereadded, the organics were separated and washed (3×) with water, thenconcentrated under reduced pressure. The crude residue was purified bynormal phase chromatography (0-100% EtOAc/hexanes) to yield Compound 4(90 mg).

Compound 4 (90 mg, 0.2 mmol) was dissolved in THF (1 mL) and 2N NaOH(160 μL, 0.8 mmol). The mixture was stirred for 2 hours. AcOH (2 mL0 wasadded and the solution was purified by reverse phase chromatography toyield Compound 5 (35 mg).

Compound 5 (8 mg, 19 μmol) was combined with DMSO (0.5 mL), H₂O₂(83 μL,816 μmol) and K₂CO₃ (23.6 mg, 171 μmol), and stirred overnight. Thereaction was quenched with 1 drop of concentrated HCl. AcOH was addedand the mixture was purified by reverse phase chromatography to yieldthe title compound (2 mg; purity 95%) as a TFA salt. MS m/z [M+H]⁺calc'd for C₂₂H₂₂FN₅O₄, 440.17; found 441.

Example 55:(2R,4R)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-[((S)-pyrrolidine-2-carbonyl)amino]-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

Compound 2 was prepared as described herein.

(S)-Pyrrolidine-2-carboxylic acid (3.6 mg, 31 μmol) and HATU (11.4 mg,30 μmol) were dissolved in DMF (3 mL) and stirred for 15 minutes at roomtemperature. Compound 2 (12.3 mg, 28 μmol) and DIPEA (15 μL, 85 μmol)were added, and the mixture was stirred at room temperature for 15minutes (LC/MS showed the desired product) then concentrated in vacuoand the residue was purified by preparative HPLC to yield the titlecompound (4 mg; purity 100%) as a TFA salt. MS m/z [M+H]⁺ calc'd forC₂₅H₂₆ClFN₆O₄, 529.17; found 530.0.

Example 56:(2R,4R)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-((S)-2,6-diaminohexanoylamino)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

Compound 2 was prepared as described herein.

(S)-2,6-Bis-t-butoxycarbonylaminohexanoic acid (10.9 mg, 31 μmol) andHATU (11.4 mg, 30 μmol) were dissolved in DMF (3 mL) and stirred for 15minutes at room temperature. Compound 2 (12.3 mg, 28 μmol) and DIPEA (15μL, 85 μmol) were added, and the mixture was stirred at room temperaturefor 15 minutes (LC/MS showed the desired product) then concentrated invacuo and the residue was dissolved in MeCN (3 mL). A solution of 4N HClin dioxane (107 mL, 427 μmol) was added, and the mixture was stirred for15 minutes at room temperature. LC/MS showed the desired mass. Thesolvent was removed in vacuo and the residue was purified by preparativeHPLC to yield the title compound (7.8 mg; purity 100%) as a TFA salt. MSm/z [M+H]⁺ calc'd for C₂₆H₃₁ClFN₇O₄, 560.21; found 560.2.

Example 57:(2R,4R)-2-((S)-2-Amino-3-phenylpropionylamino)-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

Compound 2 was prepared as described herein.

(S)-2-t-Butoxycarbonylamino-3-phenylpropionic acid (8.3 mg, 31 μmol) andHATU (11.4 mg, 30 μmol) were dissolved in DMF (3 mL) and stirred for 15minutes at room temperature. Compound 2 (12.3 mg, 28 μmol) and DIPEA (15μL, 85 μmol) were added, and the mixture was stirred at room temperaturefor 15 minutes (LC/MS showed the desired product) then concentrated invacuo and the residue was dissolved in MeCN (3 mL). A solution of 4N HClin dioxane (107 mL, 427 μmol) was added, and the mixture was stirred for15 minutes at room temperature. LC/MS showed the desired mass. Thesolvent was removed in vacuo and the residue was purified by preparativeHPLC to yield the title compound (5.5 mg; purity 100%) as a TFA salt. MSm/z [M+H]⁺ calc'd for C₂₉H₂₈ClFN₆O₄, 579.18; found 579.2.

Example 58:(S)-5-Biphenyl-4-yl-2-(tetrahydropyran-4-yl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

Compound 3 was prepared as described herein.

Compound 3 (80 mg, 230 μmol, 1.0 eq.) was dissolved in dry THF (1.5 mL).The resulting solution was cooled to −78° C., then LDA (1.8 M, 157 μL,290 μmol, 1.3 eq.) was added dropwise and the resulting solution wasstirred at −78° C. for 20 minutes. A solution of tetrahydropyran-4-one(25 mg, 280 μmol, 1.2 eq.) in THF (100 μL) was added dropwise, and theresulting mixture was stirred at −78° C. for 30 minutes. LC/MS analysisrevealed a mixture of starting material and desired product. LDA (1.8M,100 μL, 180 μmol, 0.8 eq.) was added and the mixture was stirred for 20minutes at −78° C., then tetrahydropyran-4-one (20 mg, 220 μmol, 1.0eq.) was added and the mixture was stirred for an additional 20 minutesat −78° C. and when the reaction was complete (as determined by LC/MSanalysis), the mixture was warmed to −40° C. and the reaction wasquenched with 10% citric acid (10 mL), then extracted with EtOAc (2×10mL). The aqueous phase was discarded and the combined organics weredried over Na₂SO₄, filtered and concentrated in vacuo, then purified byflash chromatography (0-60% EtOAc/hexanes, 40 minutes) to yield Compound4 (100 mg). LCMS (ESI): calc. C₂₇H₃₃NO₅=451; obs. M+H⁺=452.2. Retentiontime: 6.05 min.

Compound 4 (100 mg, 220 μmol, 1.0 eq.) was dissolved in 50% (v/v)sulfuric acid/H₂O (10 mL) and heated to 105° C. for 30 minutes. LC/MSanalysis after 30 minutes revealed ^(˜)50% of the desired product. Themixture was heated at 105° C. for 1.5 hours, cooled to room temperature,and poured onto ice. The pH was adjusted to ^(˜)6 with 4M NaOH and theresulting mixture was extracted with DCM (3×75 mL). The aqueous phasewas discarded and the combined organics were washed with saturatedaqueous NaCl (50 mL). The aqueous phase was discarded and the organicphase was dried over Na₂SO₄, filtered, and concentrated in vacuo, thenpurified by flash chromatography 0-60% EtOAc/hexanes, 40 minutes) toyield Compound 5 (100 mg; quantitative). LCMS (ESI): calc.C₂₂H₂₃NO₂=333; obs. M+H⁺=334.3. Retention time: 5.23 min.

Compound 5 (100 mg, 220 μmol, 1.0 eq.) was dissolved in MeOH (10 mL).Palladium on carbon (20 mg, 10% w/w) and AcOH (100 μL) were added andthe mixture was stirred under 1 atm. of hydrogen overnight. LC/MSanalysis revealed a mixture of starting material and desired product.The mixture was filtered through Celite®. The Celite® was then washedwith MeOH (2×20 mL) and the combined solutions were concentrated andre-dissolved in MeOH (10 mL). Palladium on carbon (10 mg, 10% w/w) wasadded and the mixture was hydrogenated on a Parr apparatus at 40 psihydrogen. LC/MS analysis revealed a mixture of starting material anddesired product. AcOH (300 μL) was added and the hydrogen pressure wasincreased to 60 psi and when the reaction was complete (as determined byLC/MS analysis), the mixture was filtered through Celite®, and theCelite® was then washed with MeOH (2×20 mL). The combined organics wereconcentrated in vacuo to yield Compound 6 (40 mg). LCMS (ESI): calc.C₂₂H₂₅NO₂=335; obs. M+H⁺=336.2. Retention time: 5.23 min.

Compound 6 (40 mg, 120 mmol, 1 eq.) and (BOC)₂O (57 mg, 280 μmol, 2.3eq.) were dissolved in dry THF (2 mL) and cooled to −40° C. for tenminutes. NaHMDS (1.0 M, 260 μL, 2.2 eq.) was added and the mixture wasstirred for 20 minutes at −40° C. and when the reaction was complete (asdetermined by LC/MS analysis), the mixture was warmed to roomtemperature and the reaction was quenched with a few drops of water,then concentrated in vacuo to yield Compound 7, which was used directlyin the next step. LCMS (ESI): calc. C₂₇H₃₃NO₄=435; obs. M+H=436.1.Retention time: 6.87 min.

Compound 7 was dissolved in a mixture of THF (2 mL) and 4N NaOH (0.5 mL)and stirred at room temperature for three days and when the reaction wascomplete (as determined by LC/MS analysis), the mixture was acidifiedwith 5% HCl (5 mL) and extracted with EtOAc (2×10 mL). The aqueous phasewas discarded and the combined organics were dried over Na₂SO₄ andpurified by preparative HPLC to yield Compound 8 (17 mg). LCMS (ESI):calc. C₂₇H₃₅NO₅=453; obs. M+H⁺=454.3. Retention time: 5.36 min.

Compound 8 (17 mg, 46 μmol, 1.0 eq.) was dissolved in 4M HCl/p-dioxane(2 mL) and stirred at room temperature for one hour and when thereaction was complete (as determined by LC/MS analysis), the mixture wasconcentrated to dryness to yield Compound 9 (17 mg; quantitative) as aTFA salt. LCMS (ESI): calc. C₂₂H₂₇NO₃=353; obs. M+H⁺=354.4. Retentiontime: 3.79 min.

Compound 9 (17 mg, 46 μmol, 1.0 eq.) was dissolved in a solution ofDIPEA (29 μL, 170 μmol, 4.0 eq.) in DMF (350 μL). A solution of1H-1,2,3-triazole-4-carboxylic acid (15 mg, 130 μmol, 3.0 eq.), HATU (25mg, 65 μmol, 1.5 eq.), and DIPEA (29 μL, 170 μmol, 4.0 eq.) in DMF (350μL) was stirred at room temperature for 20 minutes then added to theCompound 9 solution and stirred at room temperature for 30 minutes andwhen complete (as determined by LC/MS analysis), the reaction wasquenched with water (1 mL), diluted with 10% citric acid (10 mL), andextracted with EtOAc (2×20 mL). The aqueous phase was discarded and theorganic phase concentrated to dryness and purified by preparative HPLCto yield the title compound (9.6 mg; purity 99.9%). LCMS (ESI): calc.C₂₅H₂₈N₄O₄=448; obs. M+H⁺=449.1. Retention time: 4.49 min.

LC/MS Method: flow rate: 1.5 mL/min; Buffer A: 0.1% TFA/H₂O; Buffer B0.1% TFA/MeCN; gradient elution from 5% B to 100% B over 9.6 min, then100% B for 1.0 minute, detection at 254 nm.

Example 59:(S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-piperidin-4-yl-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

Compound 3 was prepared as described herein.

A solution of Compound 3 (210 mg, 552 μmol) in THF (1.8 mL) under astream of nitrogen was cooled to −78° C., followed by the dropwiseaddition of a 1.8 M THF solution of LDA (348 μL, 626 μmol). The mixturewas stirred at −78° C. for 20 minutes and a solution of4-oxo-piperidine-1-carboxylic acid t-butyl ester (114 mg, 572 μmol) indry THF (1 mL) was added dropwise. The mixture was stirred at −78° C.for an additional 20 minutes and a solution of LDA (250 μL, 450 μmol)was added dropwise, followed by the dropwise addition of a solution of4-oxo-piperidine-1-carboxylic acid t-butyl ester (85 mg, 427 μmol) indry THF (0.5 mL). After stirring at −78° C. for 20 minutes, thetemperature of the mixture was raised to −30° C. and the reaction wasquenched with 10% citric acid (10 mL). The mixture was extracted withEtOAc (3×25 mL), washed with saturated aqueous NaCl (20 mL) and driedover MgSO₄. The mixture was filtered and the filtrate was evaporated.The residue was purified by flash chromatography (0-50% hexanes/EtOAcgradient over 55 minutes). The fractions containing the desired productwere combined and evaporated. The residue was dried in vacuo at roomtemperature overnight to yield Compound 4 (250 mg). LC-MS (ESI): calc.C₃₂H₄₀ClFN₂O₆=603.1; obs. m/z 603.2 [M+H]⁺. Retention time 7.39 min.

To a solution of Compound 4 (260 mg, 215 μmol) and Et₃N (338 μL, 2.3mmol) in DCM (710 μL) was added methylsilyl chloride (193 μL, 2.3 mmol)dropwise at room temperature under a stream of nitrogen. The mixture wasstirred at room temperature for 5 minutes, then the reaction wasquenched with 2% aqueous HCl and extracted with EtOAc (3×30 mL), washedwith saturated aqueous NaCl (20 mL), and dried over MgSO₄. The mixturewas filtered and the filtrate was evaporated. The residue was purifiedby flash chromatography (0-30% hexanes/EtOAc gradient over 55 minutes).The fractions containing the desired product were combined andevaporated. The residue was dried in vacuo at room temperature overnightto yield Compound 5 (210 mg). LC-MS (ESI): calc. C₃₂H₃₈ClFN₂O₅=585.1;obs. m/z 585.2 [M+H]⁺. Retention time 7.86 min.

Compound 5 (210 mg, 360 μmol) was dissolved in 4N HCl/dioxane (8 mL, 32mmol) and stirred for 20 minutes at room temperature. The solvent wasevaporated and the residue was dried in vacuo at room temperatureovernight to yield Compound 6 as the HCl salt (150 mg). LC-MS (ESI):calc. C₂₂H₂₂ClFN₂O=384.9; obs. m/z 385.2 [M+H]⁺. Retention time 2.71min.

To a solution of Compound 6 (150 mg, 328 μmol) in a mixture ofisopropanol/MeOH (27 mL/3 mL), was added AcOH (19 μL, 328 μmol) andpalladium on carbon (10%, 90 mg). The mixture was subjected tohydrogenation (H₂, Parr apparatus, 60 psi) at room temperature for 2hours. The mixture was filtered through Celite® and evaporated. Theresidue was dried in vacuo at room temperature for 4 hours to yieldCompound 7 (146 mg). LC-MS (ESI): calc. C₂₂H₂₄ClFN₂O=386.9; obs. m/z387.1 [M+H]⁺. Retention time 4.34 min.

A solution of Compound 7 (146 mg, 318 μmol) and Et₃N (90 μL, 637 μmol)in DCM (1.5 mL) was cooled to 4° C., followed by the dropwise additionof benzyl chloroformate (45 μL, 318 μmol). The mixture was stirred at 4°C. for 20 minutes, then the reaction was quenched with 5% aqueous NaHCO₃(10 mL). The mixture was extracted with DCM (2×10 mL), and the organiclayer was washed with saturated aqueous NaCl (20 mL) and dried overMgSO₄. The mixture was filtered and the filtrate was evaporated. Theresidue was purified by flash chromatography (0-50% hexanes/EtOAcgradient over 45 minutes). The fractions containing the desired productwere combined and evaporated. The residue was dried in vacuo at roomtemperature overnight to yield Compound 8 (120 mg). LC-MS (ESI): calc.C₃₀H₃₀ClFN₂O₃=521.0; obs. m/z 521.1 [M+H]⁺. Retention time 6.70 min.

A solution of Compound 8 (120 mg, 230 μmol), Boc₂O (125 mg, 576 μmol) inTHF (1.1 ml) was cooled to −40° C., followed by the dropwise addition ofa 1M THF solution of NaHMDS (576 μL, 576 μmol). The mixture was stirredat −40° C. for 10 minutes, before being warmed to room temperature andthe reaction was quenched with 5% aqueous NaHCO₃ (10 mL). The mixturewas extracted with EtOAc (2×25 mL), washed with saturated aqueous NaCl(20 mL), and dried over MgSO₄. The mixture was filtered and the filtratewas evaporated. The residue was dried in vacuo at room temperatureovernight to yield Compound 9 (156 mg). LC-MS (ESI): calc.C₃₅H₃₈ClFN₂O₅=621.1; obs. m/z 621.3 [M+H]⁺. Retention time 7.93 min.

To a solution of Compound 9 (150 mg, 230 μmol) in a mixture of THF/water(2.5 mL/0.5 mL) was added NaOH (40 mg, 1 mmol) and H₂O₂(60 μL, 530 μmol)at room temperature. The mixture was stirred at room temperatureovernight, followed by the addition of 5% aqueous HCl to take the pH ofthe solution to 3. The mixture was extracted with EtOAc (2×20 mL),washed with saturated aqueous NaCl (10 mL), and dried over MgSO₄. Themixture was filtered and the filtrate was evaporated. The residue wasdried in vacuo at room temperature overnight to yield Compound 10 (133mg). LC-MS (ESI): calc. C₃₅H₄₀ClFN₂O₆=639.2; obs. m/z 639.3 [M+H]⁺.Retention time 7.01 min.

Compound 10 (133 mg, 210 μmol) was dissolved in 4N HCl/dioxane (5 mL, 20mmol) and stirred for 20 minutes at room temperature. The solvent wasevaporated and the residue was dried in vacuo at room temperatureovernight to yield Compound 11 as the hydrochloric salt (140 mg). LC-MS(ESI): calc. C₃₀H₃₂ClFN₂O₄=539.1; obs. m/z 539.2 [M+H]⁺. Retention time5.14 min.

To a solution of 3H-[1,2,3]triazole-4-carboxylic acid (77 mg, 688 μmol)and HATU (130 mg, 344 μmol) in DMF (1.5 mL) was added DIPEA (160 μL, 920μmol). The mixture was stirred at room temperature for 20 minutes,followed by the addition of Compound 11 (140 mg, 210 μmol). The mixturewas stirred at room temperature for 20 minutes, then the reaction wasquenched with 10% aqueous citric acid (15 mL) to pH 4. The mixture wasextracted with EtOAc (3×20 mL), washed with saturated aqueous NaCl (10mL) and dried over MgSO₄. The mixture was filtered and the filtrate wasevaporated. The residue was purified by flash chromatography (10-100%hexanes/EtOAc gradient over 45 minutes). The fractions containing thedesired product were combined and evaporated. The residue was dried invacuo at room temperature overnight to yield Compound 12 (70 mg). LC-MS(ESI): calc. C₃₃H₃₃ClFN₅O₅=634.1; obs. m/z 634.2[M+H]⁺. Retention time5.96 min.

To a solution of Compound 12 (70 mg, 110 μmol) in dioxane (1 mL) wasadded 6N aqueous HCl (2 mL, 12 mmol) under a stream of nitrogen. Themixture was stirred at 100° C. for 20 minutes, then cooled to roomtemperature. The solvent was evaporated and the residue was purified(preparative LCMS). The fractions containing desired compound werecombined and lyophilized to yield the title compound (29 mg, 53%; purityby LC-MS 95.7%) as a TFA salt. LC-MS (ESI): calc. C₂₅H₂₇ClFN₅O₃=500.0;obs. m/z 500.2 [M+H]⁺. Retention time 1.75 min.

Example 60:(S)-2-(1-Acetylpiperidin-4-yl)-5-biphenyl-4-yl-4-[(3H-[123]triazole-4-carbonyl)amino]pentanoicAcid

Compound 3 was prepared as described herein.

Compound 3 (450 mg, 1280 μmol, 1.0 eq.) was dissolved in dry THF (4.2mL). The resulting solution was cooled to −78° C., then LDA (1.8 M, 990μL, 1790 μmol, 1.4 eq.) was added dropwise and the resulting solutionwas stirred at −78° C. for 30 minutes. A solution ofN-t-butoxycarbonyl-4-piperidone (356 mg, 1790 μmol, 1.4 eq.) in THF (500μL) was added dropwise. The resulting mixture was stirred at −78° C. for20 minutes. LC/MS analysis revealed a mixture of starting material anddesired product. LDA (1.8 M, 400 μL, 720 μmol, 0.6 eq.) was added andthe mixture was stirred for 20 minutes at −78° C., then a solution ofN-t-butoxycarbonyl-4-piperidone (190 mg, 960 μmol, 0.7 eq.) in THF (200μL) was added and the resulting mixture stirred at −78° C. for one hourand when the reaction was complete (as determined by LC/MS analysis),the mixture was then warmed to −50° C. and the reaction was quenchedwith 10% citric acid (10 mL) then extracted with EtOAc (2×25 mL). Theaqueous phase was discarded and the combined organics were dried overNa₂SO₄, concentrated in vacuo, and purified by flash chromatography(0-80% EtOAc/hexanes) to yield Compound 4 (600 mg). LCMS (ESI): calc.C₃₂H₄₂N₂O₆=550; obs. [M+H]⁺=551.2. Retention time: 7.06 min.

Compound 4 (300 mg, 544 μmol, 1.0 eq.) was dissolved in a mixture ofMeCN (2 mL) and 50% (v/v) aqueous H₂SO₄ (16 mL) and heated to 130° C.for two hours and when the reaction was complete (as determined by LC/MSanalysis), the mixture was cooled to room temperature, poured onto ice,and the pH was adjusted to ^(˜)7 with 4M NaOH and the resulting mixturewas extracted with DCM (3×50 mL) and chloroform (3×50 mL). The aqueousphase was discarded and the combined organics were dried over Na₂SO₄,filtered, and concentrated in vacuo to yield Compound 5 (60 mg). LCMS(ESI): calc. C₂₂H₂₄N₂O=332; obs. [M+H]⁺=333.3. Retention time: 3.98 min.

Compound 5 (60 mg, 180 μmol, 1 eq.) was dissolved in DCM (3 mL). Et₃N(50 μL, 360 μmol 2.0 eq.) was added, followed by acetic anhydride (28μL, 270 μmol, 1.5 eq.). The mixture was stirred for 20 minutes at roomtemperature and when the reaction was complete (as determined by LC/MSanalysis), the mixture was diluted with DCM (10 mL) and saturatedaqueous NaHCO₃ (2 mL). The phases were separated and the aqueous phasewas extracted with DCM (10 mL). The aqueous phase was then discarded andthe combined organics were dried over Na₂SO₄, filtered, and concentratedin vacuo, and purified by preparative HPLC (30-60% H₂O/MeCN with 0.1%TFA, 30 mL/minute, 30 minutes) to yield Compound 6 (28 mg). LCMS (ESI):calc. C₂₄H₂₆N₂O₂=374; obs. [M+H]⁺=375.2. Retention time: 4.85 min.

Compound 6 (28 mg, 150 μmol, 1.0 eq.) was dissolved in MeOH (5 mL).Palladium on carbon (10 mg, 10% w/w) and AcOH (25 μL) were added and themixture was stirred under 1 atm. of hydrogen overnight and when thereaction was complete (as determined by LC/MS analysis), the mixturefiltered through Celite® with MeOH (20 mL) and concentrated to yieldcrude Compound 7 (32 mg; quantitative). LCMS (ESI): calc.C₂₄H₂₈N₂O₂=376; obs. [M+H]⁺=377.4. Retention time: 4.78 min.

Compound 7 (32 mg, 85 μmol, 1.0 eq.) was dissolved in dry THF (2 mL) at−40° C., followed by (BOC)₂O (37 mg, 170 μmol, 2.0 eq.). The mixture wasstirred for ten minutes then NaHMDS (1.0 M, 170 μL, 170 μmol, 2.0 eq.)was added and the mixture was stirred at −40° C. for 20 minutes and whenthe reaction was complete (as determined by LC/MS analysis), the mixturewas warmed to room temperature, the reaction quenched with water (50μL), and the mixture concentrated to dryness to yield crude Compound 8,which was used directly in the next step. LCMS (ESI): calc.C₂₉H₃₆N₂O₄=476; obs. [M+H]=477.3. Retention time: 6.15 min.

Compound 8 was dissolved in a mixture of THF (2 mL) and 4N NaOH (2 mL)and stirred at room temperature for two hours. Additional THF (1 mL) wasadded and the mixture was stirred at room temperature overnight and whenthe reaction was complete (as determined by LC/MS analysis), the pH wasadjusted to 4 with 5% aqueous HCl and the mixture extracted with EtOAc(2×20 mL). The aqueous phase was discarded and the combined organicswere extracted with saturated aqueous NaCl (5 mL). The aqueous phase wasdiscarded and the organic phase was dried over Na₂SO₄, filtered, andconcentrated to dryness to yield Compound 9 (32 mg), which was usedwithout purification in the next step. LCMS (ESI): calc. C₂₉H₃₈N₂O₅=494;obs. [M+H]⁺=495.1. Retention time: 5.39 min.

Compound 9 (32 mg, 85 μmol, 1.0 eq.) was dissolved in 4N HCl inp-dioxane (1.2 mL) and stirred at room temperature for 20 minutes andwhen the reaction was complete (as determined by LC/MS analysis), thesolution was concentrated to dryness to yield Compound 10 as thehydrochloride salt (32 mg). LCMS (ESI): calc. C₂₄H₃₀N₂O₃=394; obs.M+H=395.2. Retention time: 3.64 min.

Compound 10 (32 mg, 75 μmol, 1.0 eq.) was dissolved in DMF (500 μL).1H-1, 2, 3-triazole-4-carboxylic acid (25 mg, 221 μmol, 3.0 eq.) wasdissolved in DMF (500 μL), followed by the addition of DIPEA (51 μL, 297μmol, 4.0 eq.) and HATU (42 mg, 111 μmol, 1.5 eq.). The solutions werestirred at room temperature for 20 minutes, then combined and stirred atroom temperature for an additional 20 minutes and when the reaction wascomplete (as determined by LC/MS analysis), the mixture was diluted withwater (0.5 mL), the pH adjusted to 4 with 10% citric acid, then washedwith EtOAc (2×20 mL). The aqueous phase was discarded and the combinedorganics were extracted with saturated aqueous NaCl (10 mL). The aqueousphase was discarded and the organic phase was dried over Na₂SO₄,filtered, and concentrated in vacuo, and purified by preparative HPLC toyield the title compound (11 mg; purity 99.6%). LCMS (ESI): calc.C₂₇H₃₁N₅O₄=489; obs. M+H=490.2. Retention time: 4.23 min.

LC/MS Method: flow rate: 1.5 mL/min; Buffer A: 0.1% TFA/H₂O; Buffer B0.1% TFA/MeCN; gradient elution from 5%-100% B over 9.6 min, then 100% Bfor 1.0 minute, detection at 254 nm.

Example 61:(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]-2-[1,2,3]triazol-1-ylmethylpentanoicAcid (Compound a) and(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-4-[(3H[1,2,3]triazole-4-carbonyl)amino]-2-[1,2,3]triazol-2-ylmethylpentanoicAcid (Compound b)

(2S,4S)-4-t-Butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-hydroxymethylpentanoicacid ethyl ester (200 mg, 417 μmol) was dissolved in DCM (5 mL).Methanesulfonyl chloride (39 μL, 0.5 mmol) and Et₃N (116 μL, 833 μmol)were added. The mixture was stirred for 10 minutes and the solution waspurified by normal phase chromatography (0-100% EtOAc/hexanes) to yieldCompound 1 (198 mg).

Compound 1 (25 mg, 45 μmol) was combined with K₂CO₃ (12.4 mg, 90 μmol),1,2,3-triazole (4.3 mg, 63 μmol), and DMF (0.5 mL), and the mixture wasstirred overnight. The mixture was concentrated under reduced pressureand the residue was purified by normal phase chromatography (0-100%EtOAc/hexanes), to yield Compounds 2a (8 mg) and 2b (7 mg).

Compound 2a (8 mg, 15 μmol) was dissolved in MeCN (0.3 mL) and 4N HCl indioxane (0.3 mL). The mixture was stirred for 10 minutes andconcentrated under reduced pressure to yield Compound 3a as an HCl salt.

Compound 3a (7.0 mg, 16 μmol) was combined with DMF (0.5 mL),1H-1,2,3-triazole-5-carboxylic acid (2.0 mg, 18 μmol), HATU (6.8 mg, 18μmol) and DIPEA (8.5 μL, 49 μmol). The mixture was stirred for 30minutes after which time LCMS showed the desired product formation. Thesolution was concentrated in vacuo to yield Compound 4a which was useddirectly in the next step.

Compound 4a (8.0 mg, 15 μmol) was dissolved in THF (0.5 mL) and 1N NaOH(76 μL, 76 μmol) and stirred for 2 hours. AcOH (1 mL) was added and themixture was purified by reverse phase chromatography to yield the titlecompound (Compound a; 2 mg; purity 95%) as a TFA salt. MS m/z [M+H]⁺calc'd for C₂₃H₂₁ClFN₇O₃, 498.14; found 498.

Compound 2b (7 mg, 13 μmol) was dissolved in MeCN (0.3 mL) and 4N HCl indioxane (0.3 mL). The mixture was stirred for 10 minutes andconcentrated under reduced pressure to yield Compound 3b as an HCl salt.

Compound 3b (7.0 mg, 16 μmol) was combined with DMF (0.5 mL),1H-1,2,3-triazole-5-carboxylic acid (2.0 mg, 18 μmol), HATU (6.8 mg, 18μmol) and DIPEA (8.5 μL, 49 μmol). The mixture was stirred for 30minutes after which time LCMS showed the desired product formation. Thesolution was concentrated in vacuo to yield Compound 4b which was useddirectly in the next step.

Compound 4b (8.0 mg, 15 μmol) was dissolved in THF (0.5 mL) and 10N NaOH(76 μL, 76 μmol) and stirred for 2 hours. AcOH (1 mL) was added and themixture was purified by reverse phase chromatography to yield the titlecompound (Compound b; 2 mg; purity 95%) as a TFA salt. MS m/z [M+H]⁺calc'd for C₂₃H₂₁ClFN₇O₃, 498.14; found 498.

Example 62:(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-imidazol-1-ylmethyl-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoic Acid

Compound 1 was prepared as described herein.

Compound 1 (25 mg, 45 μmol) was combined with K₂CO₃ (12.4 mg, 90 μmol),imidazole (4.0 mg, 58 μmol), and DMF (0.5 mL), and the mixture wasstirred overnight. The solution was concentrated under reduced pressureand the residue was purified by normal phase chromatography (0-100%EtOAc/hexanes) to yield Compound 2 (15 mg).

Compound 2 (15 mg, 28 μmol) was dissolved in MeCN (0.3 mL) and 4N HCl indioxane (0.3 mL). The mixture was stirred for 10 minutes andconcentrated under reduced pressure to yield Compound 3 as an HCl salt.

Compound 3 (7.0 mg, 16 μmol) was combined with DMF (0.5 mL),1H-1,2,3-triazole-5-carboxylic acid (2.0 mg, 18 μmol), HATU (6.8 mg, 18μmol) and DIPEA (8.5 μL, 49 μmol). The mixture was stirred for 30minutes after which time LCMS showed the desired product formation,Compound 4, which was used directly in the next step.

Compound 4 (8.0 mg, 15 μmol) was dissolved in THF (0.5 mL) and NaOH (76μL, 76 μmol) and stirred for 2 hours. AcOH (1 mL) was added and themixture was purified by reverse phase chromatography to yield the titlecompound (4 mg) as a TFA salt. MS m/z [M+H]⁺ calc'd for C₂₄H₂₂ClFN₆O₃,497.14; found 497.

Example 63:(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-(1H-tetrazol-5-ylmethyl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

A solution of(2S,4S)-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-cyanomethyl-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicacid (10.5 mg, 22 μmol), sodium azide (2.8 mg, 43 μmol) and zinc bromide(4.9 mg, 22 μmol) in water (0.2 Ml) and isopropanol (0.1 Ml) was heatedat 100° C. overnight. The solution was cooled to room temperature and 3MHCl (60 μL) and EtOAc (1 mL) were added. The organic layer was isolatedand the aqueous layer was extracted with EtOAc (2×1 mL). The combinedorganic layers were washed with saturated aqueous NaCl and concentratedin vacuo. The residue (12 mg, 22 μmol) was dissolved in EtOH (22 μL) and10N NaOH (176 μL, 176 μmol) was added. The resulting solution wasstirred for 2 hours, then concentrated in vacuo. The residue waspurified by preparative HPLC to yield the title compound (2.2 mg). MSm/z [M+H]⁺ calc'd for C₂₂H₂₀ClFN₈O₃, 499.13; found 499.2.

Example 64:(2R,4R)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-(2-dimethylaminoacetylamino)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

Dimethylamino acetic acid (3.9 mg, 38 μmol) and HATU (14.5 mg, 38 μmol)were dissolved in DMF (4 mL) and stirred at room temperature for 15minutes.(2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicacid (15 mg, 35 μmol) and DIPEA (18 μL, 104 μmol) were then added andthe resulting mixture was stirred at room temperature for 15 minutes(LC/MS showed reaction completion) then concentrated in vacuo and theresidue was purified by preparative HPLC to yield the title compound(14.5 mg; purity 100%) as a TFA salt. MS m/z [M+H]⁺ calc'd forC₂₄H₂₆ClFN₆O₄, 517.17; found 517.2.

Example 65:(2R,4R)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-(2-methylaminoacetylamino)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

(t-Butoxycarbonylmethylamino) acetic acid (7.2 mg, 38 μmol) and HATU(14.5 mg, 38 μmol) were dissolved in DMF (4 mL) and stirred at roomtemperature for 15 minutes.(2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicacid (15 mg, 35 μmol) and DIPEA (18 μL, 104 μmol) were then added andthe resulting mixture was stirred at room temperature for 15 minutes(LC/MS showed reaction completion) then concentrated in vacuo and theresidue was dissolved in MeCN (2 mL). A solution of 4N HCl in dioxane(130 μL, 521 μmol) was added, and the mixture was stirred at roomtemperature for 10 min. LC/MS showed the mass of the desired product.The solvent was removed in vacuo and the residue was purified bypreparative HPLC to yield the title compound (10.4 mg; purity 100%) as aTFA salt. MS m/z [M+H]⁺ calc'd for C₂₃H₂₄ClFN₆O₄, 503.15; found 503.2.

Example 66:(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-(5-oxo-4,5-dihydro-[1,2,4]oxadiazol-3-ylmethyl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

To a solution of(2S,4S)-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-cyanomethyl-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicacid ethyl ester (11 mg, 22 μmol) in DMSO (25 μL) was addedhydroxylamine (1.3 μL, 22 μmol) and NaHCO₃ (1.8 mg, 22 μmol), and theresulting suspension was heated at 70° C. to yield a yellow solution.The solution was removed from the heat and diluted with water (0.2 mL),and the resulting suspension was extracted with EtOAc. The organiclayers were washed with saturated aqueous NaCl, dried over Na₂SO₄,filtered, and concentrated in vacuo to yield Compound 1, which was usedwithout further purification.

A solution of Compound 1 (11 mg, 22 μmol), DIPEA (9.6 μL, 55 μmol) andTFA (1.7 μL, 22 μmol) in chloroform (0.6 mL) was cooled to 0° C. Asolution of diphosgene (3.2 μL, 26 μmol) in chloroform (0.3 mL) wasadded dropwise. The resulting solution was stirred at 0° C. for 1 h, andthen at 110° C. for 30 min in a microwave. After this time, the solutionwas concentrated in vacuo to yield Compound 2, which was used withoutfurther purification.

NaOH (176 μL, 176 μmol) was added to a solution of Compound 2 (12 mg, 22μmol) in EtOH (220 μL), and the resulting mixture was stirred at roomtemperature overnight. The solution was then concentrated and theresidue was purified by preparative HPLC to yield the title compound(0.5 mg; purity 100%). MS m/z [M+H]⁺ calc'd for C₂₃H₂₀ClFN₆O₅, 515.12;found 515.2.

Example 67:(2R,4R)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-(2-methoxycarbonylaminoacetylamino)-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

(2R,4R)-2-(2-Aminoacetylamino)-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicacid (6.4 mg, 13 μmol) was dissolved in DCM (2 mL). Methyl chloroformate(1.1 μL, 14 μmol) was added, followed by DIPEA (6.9 μL, 39 μmol). Theresulting mixture was stirred at room temperature for 10 minutes (LC/MSindicated no starting material) then concentrated in vacuo and the cruderesidue was purified by reverse phase chromatography to yield the titlecompound (0.6 mg; purity 99%) as a TFA salt. MS m/z [M+H]⁺ calc'd forC₂₄H₂₄ClFN₆O₆, 547.14; found 547.

Example 68:(2S,4S)-2-[(4-Aminobutyrylamino)methyl]-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicacid

4-t-Butoxycarbonylaminobutyric acid (2.3 mg, 11 μmol) and HATU (4.3 mg,11 μmol) were dissolved in DMF (0.5 mL) and stirred at room temperaturefor 10 minutes. DIPEA (1 eq.) was added and stirred for 1 minute.(2S,4S)-2-aminomethyl-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicacid (5 mg, 11 μmol) was dissolved in DMF (1 mL) and DIPEA (5.9 μL, 34μmol) was added, followed by addition of the activated acid solution.The resulting mixture was stirred for 30 minutes, followed by theaddition of EtOAc (1 mL) and saturated aqueous NaHCO₃ (1 mL). Theorganic layer was separated and the solution was concentrated in vacuoto yield Compound 1.

Compound 1 (7 mg, 11 μmol) was dissolved in MeCN (0.4 mL) and 4N HCl indioxane (0.1 mL). The mixture was stirred for 30 minutes and the solventwas evaporated. AcOH (1 mL) was added and the solution was purified byreverse phase chromatography to yield the title compound as a TFA salt.MS m/z [M+H]⁺ calc'd for C₂₅H₂₈ClFN₆O₄, 531.18; found 531.

Example 69a:(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-morpholin-4-ylmethyl-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

(2S,4S)-4-t-Butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-methanesulfonyloxymethylpentanoicacid ethyl ester (28 mg, 50 μmol) was combined with EtOH (2 mL),followed by Na₂CO₃ (16.0 mg, 151 μmol) and morpholine (13.1 mg, 151μmol) and stirred at room temperature overnight. EtOAc (1 mL) and water(1 mL) were added, the organic layer was separated and concentratedunder reduced pressure to yield Compound 1.

Compound 1 (27 mg, 49 μmol) was dissolved in MeCN (0.5 mL) and dry 4NHCl in dioxane (0.1 mL). The mixture was stirred for 10 minutes and wasthen concentrated under reduced pressure. The residue was dissolved inAcOH (1 mL) and purified by reverse phase chromatography to yieldCompound 2 (5 mg).

1H-1,2,3-triazole-5-carboxylic acid (1.1 mg, 10.0 μmol) was combinedwith HATU (3.0 mg, 7.8 μmol) in DMF (0.5 mL) and stirred for 10 minutes;DIPEA (1 eq.) was added and the mixture was stirred for 1 minute.Compound 2 (5.0 mg, 11 μmol) was dissolved in DMF (1 mL) and DIPEA (5.8μL, 33 μmol) was added, followed by addition of the activated acidsolution. The mixture was stirred for 30 minutes to yield Compound 3.

Compound 3 (6 mg, 11 μmol) was dissolved in 1N LiOH (55.1 μL, 55 μmol)in THF (0.5 mL). The mixture was stirred for 40 minutes and AcOH wasadded. The solution was purified by reverse phase chromatography toyield the title compound. MS m/z [M+H]⁺ calc'd for C₂₅H₂₇ClFN₅O₄,516.17; found 516.

Example 69b:(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-morpholin-4-ylmethyl-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid Ethyl Ester

(2S,4S)-4-t-Butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-(toluene-4-sulfonyloxymethyl)pentanoicacid ethyl ester (35 mg, 55 μmol) was dissolved in EtOH (2 mL), followedby addition of Na₂CO₃ (10 eq.) and morpholine (24 mg, 276 μmol). Themixture was stirred at 70° C. for 2 days, at which time LCMS indicatedthe mass of the desired compound. The mixture was concentrated underreduced pressure and the crude residue was purified by reverse phasechromatography to yield Compound 1 (12 mg).

Compound 1 (12 mg, 50 μmol) was dissolved in MeCN (1 mL) and dry 4N HClin dioxane (0.5 mL). The mixture was stirred for 10 minutes and thenconcentrated under reduced pressure to yield Compound 2, which wascarried to the next step without purification.

3H-1,2,3-triazole-5-carboxylic acid (2.5 mg, 22 μmol) was combined withHATU (8.4 mg, 22 μmol) in DMF (0.3 mL) and stirred for 10 minutes; Et₃N(1 eq.) was added and the mixture was stirred for 1 minute. Compound 2(22 μmol) was dissolved in DMF (0.5 mL) and Et₃N (3.1 μL, 22 μmol) wasadded, followed by addition of the activated acid solution. The mixturewas stirred for 30 minutes, concentrated, and purified by preparativeHPLC to yield the title compound. MS m/z [M+H]⁺ calc'd forC₂₇H₃₁ClFN₅O₄, 544.21; found 544.2.

Example 70:(2R,4R)-2-(6-Aminohexanoylamino)-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

6-t-Butoxycarbonylaminohexanoic acid (8.3 mg, 36 μmol) and HATU (13.6mg, 36 μmol) were dissolved in DMF (2 mL) and stirred at roomtemperature for 15 minutes.(2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicacid ethyl ester (15 mg, 33 μmol) and DIPEA (17 μL, 98 μmol) were thenadded, and the mixture was stirred at room temperature for 15 minutes(LC/MS showed reaction completion) then concentrated in vacuo. Theresidue was dissolved in MeCN (2 mL) and a solution of 4N HCl in dioxane(122 μL, 489 μmol) was added. The mixture was stirred at roomtemperature for 20 minutes (LC/MS showed the mass of the desiredproduct) then concentrated in vacuo and the residue was dissolved inEtOH (2 mL). A solution of 1N LiOH in water (261 μL, 261 μmol) was addedand the mixture was stirred at room temperature for 30 minutes (LC/MSshowed reaction completion) then concentrated in vacuo and the residuewas purified by preparative HPLC to yield the title compound (21.3 mg;purity 100%) as a TFA salt. MS m/z [M+H]⁺ calc'd for C₂₆H₃₀ClFN₆O₄,545.20; found 545.2.

Example 71:(2R,4R)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-(4-methylamino-butyrylamino)-4-[(1H-[1,2,33]triazole-4-carbonyl)amino]pentanoicAcid

4-(t-Butoxycarbonylmethylamino)butyric acid (7.8 mg, 36 μmol) and HATU(13.6 mg, 36 μmol) were dissolved in DMF (2 mL) and stirred at roomtemperature for 15 minutes.(2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicacid ethyl ester (15 mg, 33 μmol) and DIPEA (17 μL, 98 μmol) were thenadded, and the mixture was stirred at room temperature for 15 minutes(LC/MS showed reaction completion) then concentrated in vacuo. Theresidue was dissolved in MeCN (2 mL) and a solution of 4N HCl in dioxane(122 μL, 489 μmol) was added. The mixture was stirred at roomtemperature for 20 minutes (LC/MS showed the mass of the desiredproduct) then concentrated in vacuo and the residue was dissolved inEtOH (2 mL). A solution of 1N LiOH in water (261 μL, 261 μmol) was addedand the mixture was stirred at room temperature for 30 minutes (LC/MSshowed reaction completion) then concentrated in vacuo and the residuewas purified by preparative HPLC to yield the title compound (20.5 mg;purity 100%) as a TFA salt. MS m/z [M+H]⁺ calc'd for C₂₅H₂₈ClFN₆O₄,531.18; found 531.2.

Example 72:(2R,4R)-2-(5-Amino-pentanoylamino)-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

5-t-Butoxycarbonylaminopentanoic acid (7.8 mg, 36 μmol) and HATU (13.6mg, 36 μmol) were dissolved in DMF (2 mL) and stirred at roomtemperature for 15 minutes.(2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicacid ethyl ester (15 mg, 33 μmol) and DIPEA (17 μL, 98 μmol) were thenadded, and the mixture was stirred at room temperature for 15 minutes(LC/MS showed reaction completion) then concentrated in vacuo. Theresidue was dissolved in MeCN (2 mL) and a solution of 4N HCl in dioxane(122 μL, 489 μmol) was added. The mixture was stirred at roomtemperature for 20 minutes (LC/MS showed the mass of the desiredproduct) then concentrated in vacuo and the residue was dissolved inEtOH (2 mL). A solution of 1N LiOH in water (261 μL, 261 μmol) was addedand the mixture was stirred at room temperature for 30 minutes (LC/MSshowed reaction completion) then concentrated in vacuo and the residuewas purified by preparative HPLC to yield the title compound (20.7 mg;purity 100%) as a TFA salt. MS m/z [M+H]⁺ calc'd for C₂₅H₂₈ClFN₆O₄,531.18; found 531.2.

Example 73:(2R,4R)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-(4-dimethylaminobutyrylamino)-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

4-Dimethylaminobutyric acid hydrochloride (6.0 mg, 36 μmol) and HATU(13.6 mg, 36 μmol) were dissolved in DMF (2 mL) and stirred at roomtemperature for 15 minutes.(2R,4R)-2-Amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicacid ethyl ester (15 mg, 33 μmol) and DIPEA (17 μL, 98 μmol) were thenadded, and the mixture was stirred at room temperature for 15 minutes(LC/MS showed reaction completion) then concentrated in vacuo. Theresidue was dissolved in EtOH (2 mL). A solution of 1N LiOH in water(261 μL, 261 μmol) was added and the mixture was stirred at roomtemperature for 30 minutes (LC/MS showed reaction completion) thenconcentrated in vacuo and the residue was purified by preparative HPLCto yield the title compound (24.3 mg; purity 100%) as a TFA salt. MS m/z[M+H]⁺ calc'd for C₂₆H₃₀ClFN₆O₄, 545.20; found 545.2.

Example 74:(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-[(3-methoxypropylamino)-methyl]-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

To a stirred solution of(2S,4S)-4-t-butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-methanesulfonyloxymethylpentanoicacid ethyl ester (60 mg, 108 μmol) in EtOH (2 mL), was added2-methoxypropylamine (19.2 mg, 215 μmol). The resulting mixture wasstirred at 50° C. overnight. EtOAc (2 mL) and water (1 mL) were added,the organic layer was separated and washed with water (3×), dried overNa₂SO₄, then concentrated under reduced pressure and purified by normalphase chromatography (0-60% EtOAc:hexanes) to yield Compound 1 (15 mg).

Compound 1 (10.0 mg, 18 μmol) was dissolved in MeCN (0.5 mL) and dry 4NHCl in dioxane (0.3 mL). The mixture was stirred for 10 minutes and wasthen concentrated under reduced pressure to yield Compound 2 as an HClsalt.

1H-1,2,3-triazole-5-carboxylic acid (2.3 mg, 20 μmol) was combined withHATU (5.9 mg, 15 μmol) in DMF (0.5 mL) and stirred for 10 minutes; DIPEA(1 eq.) was added and the mixture was stirred for 1 minute. Compound 2(10.0 mg, 22 μmol) was dissolved in DMF (1 mL) and DIPEA (11.6 μL, 66μmol) was added, followed by addition of the activated acid solution.The mixture was stirred for 30 minutes and then concentrated in vacuo toyield Compound 3.

To the crude solution of Compound 3 (10.0 mg, 18 μmol) was added 1N LiOH(92 μL, 92 μmol) and THF (0.5 mL), followed by MeOH (0.1 mL). Themixture was stirred for 1 hour and AcOH (1 mL) was added. The solutionwas purified by reverse phase chromatography to yield the title compound(2 mg; purity 95%) as a TFA salt. MS m/z [M+H]⁺ calc'd forC₂₅H₂₉ClFN₅O₄, 518.19; found 518.

Example 75:(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-dimethylaminomethyl-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

To a stirred solution of(2S,4S)-4-t-Butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-methanesulfonyloxymethylpentanoicacid ethyl ester (60 mg, 108 μmol) in EtOH (2 mL), was addeddimethylamine in THF (108 μL, 215 μmol). The resulting mixture wasstirred at 50° C. overnight. EtOAc (2 mL) and water (2 mL) were added.The organic layer was separated and washed with water (3×), thenconcentrated under reduced pressure and purified by normal phasechromatography (0-60% EtOAc:hexanes) to yield Compound 1 (10 mg).

Compound 1 (9.2 mg, 18 μmol) was dissolved in MeCN (0.5 mL) and dry 4NHCl in dioxane (0.3 mL). The mixture was stirred for 10 minutes and thenconcentrated under reduced pressure to yield Compound 2 as an HCl salt.

1H-1,2,3-triazole-5-carboxylic acid (2.3 mg, 20 μmol) was combined withHATU (5.9 mg, 15 μmol) in DMF (0.5 mL) and stirred for 10 minutes; DIPEA(1 eq.) was added and the mixture was stirred for 1 minute. Compound 2(9.0 mg, 22 μmol) was dissolved in DMF (1 mL) and DIPEA (11.6 μL, 66μmol) was added, followed by addition of the activated acid solution.The mixture was stirred for 30 minutes and the solution was concentratedin vacuo to yield Compound 3.

To a solution of crude Compound 3 (9.0 mg, 18 μmol) was added 1N LiOH(92 μL, 92 μmol) and THF (0.5 mL), followed by MeOH (0.1 mL). Themixture was stirred for 1 hour and AcOH was added. The solution waspurified by reverse phase chromatography to yield the title compound (2mg; purity 95%) as a TFA salt. MS m/z [M+H]⁺ calc'd for C₂₃H₂₅ClFN₅O₃,474.16; found 474.

Example 76:(S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-pyridin-2-yl-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

A 1M solution of lithium bis(trimethylsilyl)amide in hexanes (88 μL, 88μmol) in THF (110 μL) was cooled to 0° C. and methyl2-(pyridin-2-yl)acetate (12 μL, 88 μmol) was added. After stirring atthis temperature for 30 minutes, a solution of (R)-t-butyl4-((5′-chloro-2′-fluoro-[1,1′-biphenyl]-4-yl)methyl)-1,2,3-oxathiazolidine-3-carboxylate2,2-dioxide (46 mg, 105 μmol) in THF (0.5 mL) was added. The resultingmixture was stirred at this temperature for 1 hour and then slowlywarmed up to room temperature overnight. 1N HCl (0.5 mL) was added andthe solution was stirred at room temperature for 10 minutes. DCM (1.5mL) was added, the layers were separated and the aqueous layer wasextracted with DCM (2×1.5 mL). The combined organic layers were driedover Na₂SO₄, filtered and concentrated. The crude product was purifiedby column chromatography (0-30% EtOAc in hexanes over 20 minutes) toyield Compound 1 (21.8 mg) as a clear oil.

A solution of Compound 1 (8.9 mg, 18 μmol) in HCl (88 μL, 351 μmol) wasstirred at room temperature for 20 minutes. After this time, LCMSindicated that the BOC group had been cleaved so the solution wasconcentrated in vacuo. In a separate flask, a solution of3H-[1,2,3]triazole-4-carboxylic acid (2.4 mg, 21 μmol) and HATU (8.0 mg,21 μmol) in DMF (180 μL) was stirred at room temperature for 30 minutes.After this time, a solution of the crude amine in DMF (180 μL) wasadded, followed by DIPEA (9.2 μL, 53 μmol). The resulting solution wasstirred overnight at room temperature. LCMS indicated that the reactionwas complete and the solution was concentrated in vacuo to yieldCompound 2 (8.9 mg), which was used without further purification.

To a solution of Compound 2 (9.1 mg, 18 μmol) in MeOH (180 μL) was added10N NaOH (144 μL, 144 μmol). The resulting solution was stirred at roomtemperature overnight. LCMS indicated that a large amount of startingmaterial was present so additional 10N NaOH (144 μL, 144 μmol) wasadded. After stirring at room temperature for 2 hours, the reaction wascomplete and the solution was concentrated in vacuo. The residue waspurified by preparative HPLC to yield the title compound (3.8 mg; purity97%) as a mixture of diastereomers at the pyridine center. MS m/z [M+H]⁺calc'd for C₂₅H₂₁ClFN₅O₃, 494.13; found 494.0.

Example 77:(S)-5-(5′-Chloro-2′-fluoro-biphenyl-4-yl)-2-pyridin-3-yl-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid (diastereomers a and b)

A 1M solution of lithium bis(trimethylsilyl)amide in hexanes (87 μL, 87μmol) in THF (110 μL) was cooled to 0° C. and ethyl2-(pyridin-3-yl)acetate (13 μL, 87 μmol) was added. After stirring atthis temperature for 30 minutes, a solution of (R)-t-butyl4-((5′-chloro-2′-fluoro-[1,1′-biphenyl]-4-yl)methyl)-1,2,3-oxathiazolidine-3-carboxylate2,2-dioxide (46 mg, 104 μmol) in THF (0.5 mL) was added. The resultingmixture was stirred at this temperature for 1 hour and then slowlywarmed up to room temperature overnight. 1N HCl (0.5 mL) was added andthe solution was stirred at room temperature for 10 minutes. DCM (1.5mL) was added, the layers were separated and the aqueous layer wasextracted with DCM (2×1.5 mL). The combined organic layers were driedover Na₂SO₄, filtered and concentrated. The crude product was purifiedby column chromatography (0-30% EtOAc in hexanes over 20 minutes) toyield Compound 1 (9.7 mg) as a clear oil.

To a solution of Compound 1 (9.7 mg, 18 μmol) in dioxane (180 μL) wasadded HCl (92 μL, 368 μmol). The resulting solution was stirred at roomtemperature for 2 hours, and then concentrated in vacuo. In a separateflask, a solution of 3H-[1,2,3]triazole-4-carboxylic acid (2.5 mg, 22μmol) and HATU (8.4 mg, 22 μmol) in DMF (180 μL) was stirred at roomtemperature for 30 minutes. After this time, a solution of the crudeamine in DMF (180 μL) was added, followed by DIPEA (9.6 μL, 55 μmol).The resulting solution was stirred for 1 hour at room temperature thenconcentrated in vacuo when the reaction was deemed complete by LCMS toyield Compound 2 (9.6 mg), which was used without further purification.

To a solution of Compound 2 (9.4 mg, 18 μmol) in EtOH (180 μL) was added10N NaOH (288 μL, 288 μmol). The resulting solution was stirred at roomtemperature for 1 hour and then concentrated in vacuo. The residue waspurified by preparative HPLC to yield the title compound (diastereomera; 3.1 mg; purity 96% and diastereomer b; 1.3 mg; purity 100%). MS m/z[M+H]⁺ calc'd for C₂₅H₂₁ClFN₅O₃, 494.13; found 494.2.

Example 78:(S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-thiophen-2-yl-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

A 1M solution of lithium bis(trimethylsilyl)amide in hexanes (87 μL, 87μmol) in THF (110 μL) was cooled to 0° C. and ethyl2-(thiophen-2-yl)acetate (13 μL, 87 μmol) was added. After stirring atthis temperature for 30 minutes, a solution of (R)-t-butyl4-((5′-chloro-2′-fluoro-[1,1′-biphenyl]-4-yl)methyl)-1,2,3-oxathiazolidine-3-carboxylate2,2-dioxide (46 mg, 104 μmol) in THF (0.5 mL) was added. The resultingmixture was stirred at this temperature for 1 hour and then slowlywarmed up to room temperature overnight. 1N HCl (0.5 mL) was added andthe solution was stirred at room temperature for 10 minutes. DCM (1.5mL) was added, the layers were separated and the aqueous layer wasextracted with DCM (2×1.5 mL). The combined organic layers were driedover Na₂SO₄, filtered and concentrated. The crude product was purifiedby column chromatography (0-30% EtOAc in hexanes over 20 minutes) toyield Compound 1 (15.9 mg) as a clear oil.

To a solution of Compound 1 (15.9 mg, 30 μmol) in dioxane (0.3 mL) wasadded HCl (149 μL, 598 μmol). The resulting solution was stirred at roomtemperature for 2 hours, and then concentrated in vacuo. In a separateflask, a solution of 3H-[1,2,3]triazole-4-carboxylic acid (4.1 mg, 36μmol) and HATU (14 mg, 36 μmol) in DMF (0.3 mL) was stirred at roomtemperature for 30 minutes. After this time, a solution of the crudeamine in DMF (0.3 mL) was added, followed by DIPEA (16 μL, 90 μmol). Theresulting solution was stirred for 1 hour at room temperature thenconcentrated in vacuo when the reaction was deemed complete by LCMS toyield Compound 2 (16 mg), which was used without further purification.

To a solution of Compound 2 (15.8 mg, 30 μmol) in EtOH (0.3 mL) wasadded 10N NaOH (240 μL, 240 μmol). The resulting solution was stirred atroom temperature for 1 hour and then concentrated in vacuo. The residuewas purified by preparative HPLC to yield the title compound (2.6 mg;purity 99.5%) as a mixture of diastereomers at the point of attachmentof the thiophene ring. MS m/z [M+H]⁺ calc'd for C₂₄H₂₀ClFN₄O₃S, 499.09;found 499.0.

Example 79:(S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-thiophen-3-yl-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

A 1M solution of lithium bis(trimethylsilyl)amide in hexanes (87 μL, 87μmol) in THF (110 μL) was cooled to 0° C. and ethyl2-(thiophen-3-yl)acetate (13 μL, 87 μmol) was added. After stirring atthis temperature for 30 minutes, a solution of (R)-t-butyl4-((5′-chloro-2′-fluoro-[1,1′-biphenyl]-4-yl)methyl)-1,2,3-oxathiazolidine-3-carboxylate2,2-dioxide (46 mg, 104 μmol) in THF (0.5 mL) was added. The resultingmixture was stirred at this temperature for 1 hour and then slowlywarmed up to room temperature overnight. 1N HCl (0.5 mL) was added andthe solution was stirred at room temperature for 10 minutes. DCM (1.5mL) was added, the layers were separated and the aqueous layer wasextracted with DCM (2×1.5 mL). The combined organic layers were driedover Na₂SO₄, filtered and concentrated. The crude product was purifiedby column chromatography (0-30% EtOAc in hexanes over 20 minutes) toyield Compound 1 (51.3 mg) as a clear oil.

A solution of Compound 1 (51.3 mg, 96 μmol) in HCl (482 μL, 1.9 mmol)was stirred at room temperature for 2 hours, and then concentrated invacuo. In a separate flask, a solution of3H-[1,2,3]triazole-4-carboxylic acid (13 mg, 116 μmol) and HATU (44 mg,116 μmol) in DMF was stirred at room temperature for 30 minutes. Afterthis time, a solution of the crude amine in DMF was added, followed byDIPEA (51 μL, 289 μmol). The resulting solution was stirred for 1 hourat room temperature then concentrated in vacuo when the reaction wasdeemed complete by LCMS to yield Compound 2 (96 mg), which was usedwithout further purification.

To a solution of Compound 2 (50.6 mg, 96 μmol) in EtOH (1.0 mL) wasadded 10N NaOH (768 μL, 768 μmol). The resulting solution was stirred atroom temperature for 2 hours and then concentrated in vacuo. The residuewas purified by preparative HPLC to yield the title compound (3.3 mg;purity 100%) as a mixture of diastereomers at the point of attachment ofthe thiophene ring. MS m/z [M+H]⁺ calc'd for C₂₄H₂₀ClFN₄O₃S, 499.09;found 499.2.

Example 80:(2S,4S)-5-(3′-Bromobiphenyl-4-yl)-2-methoxymethyl-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

DIPEA (42 μL, 243 μmol) was added to a solution of(2S,4S)-4-amino-5-(3′-bromobiphenyl-4-yl)-2-methoxymethylpentanoic acidethyl ester (34 mg, 81 μmol), 3H-[1,2,3]triazole-4-carboxylic acid (11.0mg, 97 μmol) and HATU (46.2 mg, 122 μmol) in DMF (0.3 mL), and theresulting mixture was stirred at room temperature for 15 minutes. 5.0 Maqueous LiOH (130 μL, 649 μmol) was added dropwise and the mixture wasstirred at room temperature for 15 hours then purified by preparativeHPLC to yield the title compound (23.5 mg) as a TFA salt. MS m/z [M+H]⁺calc'd for C₂₂H₂₃BrN₄O₄, 487.09; found 487.2.

Example 81:(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-[(2-fluoroethylamino)methyl]-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

(2S,4S)-4-t-Butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-(toluene-4-sulfonyloxymethyl)pentanoicacid ethyl ester (35 mg, 55 μmol) was dissolved in EtOH (2 mL), followedby addition of Na₂CO₃ (10 eq.) and 2-fluoroethylamine (17 mg, 276 μmol).The mixture was stirred at 70° C. for 2 days, at which time LCMSindicated the mass of the desired compound. The mixture was concentratedunder reduced pressure and the crude residue was purified by reversephase chromatography to yield Compound 1 (4 mg).

Compound 1 (4 mg, 50 μmol) was dissolved in MeCN (1 mL) and dry 4N HClin dioxane (0.5 mL). The mixture was stirred for 10 minutes and thenconcentrated under reduced pressure to yield Compound 2, which wascarried to the next step without 5 purification.

3H-1,2,3-triazole-5-carboxylic acid (2.5 mg, 22 μmol) was combined withHATU (8.4 mg, 22 μmol) in DMF (0.3 mL) and stirred for 10 minutes; Et₃N(1 eq.) was added and the mixture was stirred for 1 minute. Compound 2(22 μmol) was dissolved in DMF (0.5 mL) and Et₃N (3.1 μL, 22 μmol) wasadded, followed by addition of the activated acid solution. The mixturewas stirred for 30 minutes and concentrated to yield Compound 3, whichwas carried to the next step without purification.

To crude Compound 3 (22 μmol) was added 1N LiOH (88 μL, 88 μmol), THF(0.3 mL), and 2 drops of MeOH. The mixture was stirred overnight andAcOH was added. The solution was purified by purified by reverse phasechromatography to yield the title compound (0.6 mg) as a TFA salt. MSm/z [M+H]⁺ calc'd for C₂₃H₂₄ClF₂N₅O₃, 492.15; found 492.2.

Example 82:(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-[(2,2-difluoroethylamino)methyl]-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid (Compound a) and(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-[(2,2-difluoroethylamino)methyl]-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid Ethyl Ester (Compound b)

(2S,4S)-4-t-Butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-(toluene-4-sulfonyloxymethyl)pentanoicacid ethyl ester (35 mg, 55 μmol) was dissolved in EtOH (2 mL), followedby addition of Na₂CO₃ (10 eq.) and 2,2-fifluoroethylamine (22 mg, 276μmol). The mixture was stirred at 70° C. for 2 days, at which time LCMSindicated the mass of the desired compound. The mixture was concentratedunder reduced pressure and the crude residue was purified by reversephase chromatography to yield Compound 1 (6 mg).

Compound 1 (6 mg, 50 μmol) was dissolved in MeCN (1 mL) and dry 4N HClin dioxane (0.5 mL). The mixture was stirred for 10 minutes and thenconcentrated under reduced pressure to yield Compound 2, which wascarried to the next step without purification.

3H-1,2,3-triazole-5-carboxylic acid (2.5 mg, 22 μmol) was combined withHATU (8.4 mg, 22 μmol) in DMF (0.3 mL) and stirred for 10 minutes; Et₃N(1 eq.) was added and the mixture was stirred for 1 minute. Compound 2(22 μmol) was dissolved in DMF (0.5 mL) and Et₃N (3.1 μL, 22 μmol) wasadded, followed by addition of the activated acid solution. The mixturewas stirred for 30 minutes and concentrated to yield Compound 3, whichwas carried to the next step without purification.

To the crude Compound 3 (22 μmol) was added 1N LiOH (88 μL, 88 μmol),THF (0.3 mL), and 2 drops of MeOH. The mixture was stirred overnight andAcOH was added. The solution was purified by purified by reverse phasechromatography to yield Compound a (1.1 mg) as a TFA salt. MS m/z [M+H]⁺calc'd for C₂₃H₂₃ClF₃N₅O₃, 510.14; found 510.2.

1H-1,2,3-triazole-4-carboxylic acid (2.6 mg, 23 μmol) was combined withHATU (9.6 mg, 25 μmol) in DMF (3.0 mL) and stirred at room temperaturefor 15 minutes. Compound 2 (13 mg, 29 μmol) was dissolved in DIPEA (12μL, 69 μmol) and combined with the activated acid solution. The mixturewas stirred at room temperature for 15 minutes, after which time LCMSindicated desired product formation. The solvent was removed in vacuoand the crude residue was purified by reverse phase chromatography toyield Compound b (0.8 mg) as a TFA salt. MS m/z [M+H]⁺ calc'd forC₂₅H₂₇ClF₃N₅O₃, 538.18; found 538.

Example 83:(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-(3-hydroxyazetidin-1-ylmethyl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid Ethyl Ester (Compound a) and(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-(3-hydroxyazetidin-1-ylmethyl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid (Compound b)

(2S,4S)-4-t-Butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-(toluene-4-sulfonyloxymethyl)pentanoicacid ethyl ester (35 mg, 55 μmol) was dissolved in EtOH (2 mL), followedby addition of Na₂CO₃ (10 eq.) and azetidin-3-ol (20 mg, 276 μmol). Themixture was stirred at 70° C. for 2 days, at which time LCMS indicatedthe mass of the desired compound. The mixture was concentrated underreduced pressure and the crude residue was purified by reverse phasechromatography to yield Compound 1 (13 mg).

Compound 1 (13 mg, 50 μmol) was dissolved in MeCN (1 mL) and dry 4N HClin dioxane (0.5 mL). The mixture was stirred for 10 minutes and thenconcentrated under reduced pressure to yield Compound 2, which wascarried to the next step without purification.

3H-1,2,3-triazole-5-carboxylic acid (2.5 mg, 22 μmol) was combined withHATU (8.4 mg, 22 μmol) in DMF (0.3 mL) and stirred for 10 minutes; Et₃N(1 eq.) was added and the mixture was stirred for 1 minute. Compound 2(22 μmol) was dissolved in DMF (0.5 mL) and Et₃N (3.1 μL, 22 μmol) wasadded, followed by addition of the activated acid solution. The mixturewas stirred for 30 minutes, concentrated, and purified by preparativeHPLC to yield Compound a (7 mg) as a TFA salt. MS m/z [M+H]⁺ calc'd forC₂₆H₂₉ClFN₅O₄, 530.19; found 530.2.

Compound a (22 μmol) was combined with 1N LiOH (88 μL, 88 μmol), THF(0.3 mL), and 2 drops of MeOH. The mixture was stirred overnight andAcOH was added. The solution was purified by purified by reverse phasechromatography to yield Compound b (3 mg) as a TFA salt. MS m/z [M+H]⁺calc'd for C₂₄H₂₅ClFN₅O₄, 502.16; found 502.

Example 84:(2S,4S)-2-Azetidin-1-ylmethyl-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(3H-[12.3]triazole-4-carbonyl)amino]pentanoicAcid Ethyl Ester (Compound a) and(2S,4S)-2-Azetidin-1-ylmethyl-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid (Compound b)

(2S,4S)-4-t-Butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-(toluene-4-sulfonyloxymethyl)pentanoicacid ethyl ester (35 mg, 55 μmol) was dissolved in EtOH (2 mL), followedby addition of Na₂CO₃ (10 eq.) and azetidine (15 mg, 276 μmol). Themixture was stirred at 70° C. for 2 days, at which time LCMS indicatedthe mass of the desired compound. The mixture was concentrated underreduced pressure and the crude residue was purified by reverse phasechromatography to yield Compound 1 (15 mg).

Compound 1 (15 mg, 50 μmol) was dissolved in MeCN (1 mL) and dry 4N HClin dioxane (0.5 mL). The mixture was stirred for 10 minutes and thenconcentrated under reduced pressure to yield Compound 2, which wascarried to the next step without purification.

3H-1,2,3-triazole-5-carboxylic acid (2.5 mg, 22 μmol) was combined withHATU (8.4 mg, 22 μmol) in DMF (0.3 mL) and stirred for 10 minutes; Et₃N(1 eq.) was added and the mixture was stirred for 1 minute. Compound 2(22 μmol) was dissolved in DMF (0.5 mL) and Et₃N (3.1 μL, 22 μmol) wasadded, followed by addition of the activated acid solution. The mixturewas stirred for 30 minutes, concentrated, and purified by preparativeHPLC to yield Compound a (8 mg) as a TFA salt. MS m/z [M+H]⁺ calc'd forC₂₆H₂₉ClFN₅O₃, 514.19; found 514.2.

Compound a (22 μmol) was combined with 1N LiOH (88 μL, 88 μmol), THF(0.3 mL), and 2 drops of MeOH. The mixture was stirred overnight andAcOH was added. The solution was purified by purified by reverse phasechromatography to yield Compound b (3 mg) as a TFA salt. MS m/z [M+H]⁺calc'd for C₂₄H₂₅ClFN₅O₃, 486.16; found 486.

Example 85:(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-{[(2-methoxyethyl)methylamino]methyl}-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid (Compound a) and(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-{[(2-methoxyethyl)methylamino]methyl}-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid Ethyl Ester (Compound b)

(2S,4S)-4-t-Butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-(toluene-4-sulfonyloxymethyl)pentanoicacid ethyl ester (35 mg, 55 μmol) was dissolved in EtOH (2 mL), followedby addition of Na₂CO₃ (10 eq.) and (2-methoxyethyl)methylamine (24 mg,276 μmol). The mixture was stirred at 70° C. for 2 days, at which timeLCMS indicated the mass of the desired compound. The mixture wasconcentrated under reduced pressure and the crude residue was purifiedby reverse phase chromatography to yield Compound 1 (10 mg).

Compound 1 (10 mg, 50 μmol) was dissolved in MeCN (1 mL) and dry 4N HClin dioxane (0.5 mL). The mixture was stirred for 10 minutes and thenconcentrated under reduced pressure to yield Compound 2, which wascarried to the next step without purification.

3H-1,2,3-triazole-5-carboxylic acid (2.5 mg, 22 μmol) was combined withHATU (8.4 mg, 22 μmol) in DMF (0.3 mL) and stirred for 10 minutes; Et₃N(1 eq.) was added and the mixture was stirred for 1 minute. Compound 2(22 μmol) was dissolved in DMF (0.5 mL) and Et₃N (3.1 μL, 22 μmol) wasadded, followed by addition of the activated acid solution. The mixturewas stirred for 30 minutes and concentrated to yield Compound 3, whichwas carried to the next step without purification.

To the crude Compound 3 (22 μmol) was added 1N LiOH (88 μL, 88 μmol),THF (0.3 mL), and 2 drops of MeOH. The mixture was stirred overnight andAcOH was added. The solution was purified by purified by reverse phasechromatography to yield Compound a (3 mg). MS m/z [M+H]⁺ calc'd forC₂₅H₂₉ClFN₅O₄, 518.19; found 518.

3H-1,2,3-triazole-5-carboxylic acid (3.0 mg, 27 μmol) was combined withHATU (10.1 mg, 27 μmol) in DMF (0.5 mL); DIPEA (4.7 μL, 27 μmol) wasadded and the mixture was stirred for 5 minutes. Compound 2 (12 mg, 27μmol) was dissolved in DMF (0.5 mL) and DIPEA (13.9 μL, 80 μmol) andcombined with the activated acid solution. The mixture was stirred for10 minutes, at which time LCMS indicated the mass of the desiredcompound. The solvent was removed under reduced pressure and the residuewas purified by reverse phase chromatography to yield Compound b (8 mg)as a TFA salt. MS m/z [M+H]⁺ calc'd for C₂₇H₃₃ClFN₅O₄, 546.22; found546.

Example 86:(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-methylaminomethyl-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid Ethyl Ester

(2S,4S)-4-t-Butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-(toluene-4-sulfonyloxymethyl)pentanoicacid ethyl ester (35 mg, 55 μmol) was dissolved in EtOH (2 mL), followedby addition of Na₂CO₃ (10 eq.) and methylamine (8 mg, 276 μmol). Themixture was stirred at 70° C. for 2 days, at which time LCMS indicatedthe mass of the desired compound. The mixture was concentrated underreduced pressure and the crude residue was purified by reverse phasechromatography to yield Compound 1 (6 mg).

Compound 1 (6 mg, 50 μmol) was dissolved in MeCN (1 mL) and dry 4N HClin dioxane (0.5 mL). The mixture was stirred for 10 minutes and thenconcentrated under reduced pressure to yield Compound 2, which wascarried to the next step without purification.

3H-1,2,3-triazole-5-carboxylic acid (2.5 mg, 22 μmol) was combined withHATU (8.4 mg, 22 μmol) in DMF (0.3 mL) and stirred for 10 minutes; Et₃N(1 eq.) was added and the mixture was stirred for 1 minute. Compound 2(22 μmol) was dissolved in DMF (0.5 mL) and Et₃N (3.1 μL, 22 μmol) wasadded, followed by addition of the activated acid solution. The mixturewas stirred for 30 minutes, concentrated, and purified by preparativeHPLC to yield the title compound. MS m/z [M+H]⁺ calc'd forC₂₄H₂₇ClFN₅O₃, 488.18; found 488.2.

Example 87:(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-[(3-hydroxypropylamino)methyl]-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid Ethyl Ester (Compound a) and(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-[(3-hydroxypropylamino)methyl]-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid (Compound b)

(2S,4S)-2-(4-Bromobenzenesulfonyloxymethyl)-4-t-butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)pentanoicacid ethyl ester (100 mg, 143 μmol) was dissolved in EtOH (3 mL),followed by addition of Na₂CO₃ (152 mg, 1.4 mmol) and 3-aminopropan-1-ol(54 mg, 715 μmol). The resulting mixture was stirred for 2 days at 70°C., at which time LCMS indicated the mass of the desired compound. Themixture was concentrated under reduced pressure and the crude residuewas dissolved in AcOH (4 mL) and H₂O (1 mL) and purified by reversephase chromatography (10-80% MeCN/H₂O gradient) to yield Compound 1 (25mg).

Compound 1 (27 mg; 50 μmol) was dissolved in MeCN (1 mL) and dry 4N HClin dioxane (0.5 mL). The mixture was stirred at room temperature for 10minutes and then concentrated under reduced pressure to yield Compound 2as an HCl salt, which was used in without purification.

1H-1,2,3-triazole-5-carboxylic acid (3.4 mg, 30 μmol) was combined withHATU (11 mg, 30 μmol) in DMF (0.3 mL) stirred at room temperature for 10minutes; DIPEA (1 eq.) was added and the mixture was stirred for 1minute. Compound 2 (10 mg, 30 μmol) was dissolved in DMF (0.5 mL) andDIPEA (5.2 μL, 30 μmol) was added, followed by addition of the activatedacid solution. The mixture was stirred at room temperature for 30minutes, after which time LCMS indicated desired product formation. Halfof the crude product was purified using reverse phase chromatography toyield Compound a as a TFA salt (1 mg). MS m/z [M+H]⁺ calc'd forC₂₆H₃₁ClFN₅O₄, 532.21; found 532. Half of the crude product was carriedto the next step without further purification.

Crude Compound a (12 mg, 22 μmol) was dissolved in THF (0.3 mL), 1N LiOH(88 μL, 88 μmol) and MeOH (2 drops), and stirred for 2 hours at 50° C.AcOH (2 mL) was added and the solution was purified by reverse phasechromatography to yield Compound b (4 mg) as a TFA salt. MS m/z [M+H]⁺calc'd for C₂₄H₂₇ClFN₅O₄, 504.17; found 504.

Example 88:(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-(3-cyanoazetidin-1-ylmethyl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid Ethyl Ester (Compound a) and(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-(3-cyanoazetidin-1-ylmethyl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid (Compound b)

(2S,4S)-2-(4-Bromobenzenesulfonyloxymethyl)-4-t-butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)pentanoicacid ethyl ester (100 mg, 143 μmol) was dissolved in EtOH (3 mL),followed by addition of Na₂CO₃ (152 mg, 1.4 mmol) andazetidine-3-carbonitrile (59 mg, 715 μmol). The resulting mixture wasstirred for 2 days at 70° C., at which time LCMS indicated the mass ofthe desired compound. The mixture was concentrated under reducedpressure and the crude residue was dissolved in AcOH (4 mL) and H₂O (1mL) and purified by reverse phase chromatography (10-80% MeCN/H₂Ogradient) to yield Compound 1 (30 mg).

Compound 1 (27 mg; 50 μmol) was dissolved in MeCN (1 mL) and dry 4N HClin dioxane (0.5 mL). The mixture was stirred for 10 minutes and thenconcentrated under reduced pressure to yield Compound 2 as an HCl salt,which was used without purification.

1H-1,2,3-triazole-5-carboxylic acid (3.4 mg, 30 μmol) was combined withHATU (11 mg, 30 μmol) in DMF (0.3 mL) and stirred at room temperaturefor 10 minutes; DIPEA (1 eq.) was added and the mixture was stirred for1 minute. Compound 2 (10 mg, mol) was dissolved in DMF (0.5 mL) andDIPEA (5.2 μL, 30 μmol) was added, followed by addition of the activatedacid solution. The mixture was stirred at room temperature for 30minutes, after which time LCMS indicated desired product formation. Halfof the crude product was purified using reverse phase chromatography toyield Compound a (7.7 mg) as a TFA salt. MS m/z [M+H]⁺ calc'd forC₂₇H₂₈ClFN₆O₃, 539.19; found 539. Half of the crude product was carriedto the next step without further purification.

Crude Compound a (12 mg, 22 μmol) was dissolved in THF (0.3 mL), 1N LiOH(88 μL, 88 μmol) and MeOH (2 drops), and stirred for 2 hours at 50° C.AcOH (3 mL) was added and the solution was purified by reverse phasechromatography to yield Compound b (3 mg) as a TFA salt. MS m/z [M+H]⁺calc'd for C₂₅H₂₄ClFN₆O₃, 511.16; found 511.

Example 89:(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-(3,3-dimethylazetidin-1-ylmethyl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid Ethyl Ester (Compound a) and(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-(3,3-dimethylazetidin-1-ylmethyl)-4-[(3H-[1,23]triazole-4-carbonyl)amino]pentanoicAcid (Compound b)

(2S,4S)-2-(4-Bromobenzenesulfonyloxymethyl)-4-t-butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)pentanoicacid ethyl ester (100 mg, 143 μmol) was dissolved in EtOH (3 mL),followed by addition of Na₂CO₃ (152 mg, 1.4 mmol) and3,3-dimethylazetidine (61 mg, 715 μmol). The resulting mixture wasstirred for 2 days at 70° C., at which time LCMS indicated the mass ofthe desired compound. The mixture was concentrated under reducedpressure and the crude residue was dissolved in AcOH (4 mL) and H₂O (1mL) and purified by reverse phase chromatography (10-80% MeCN/H₂Ogradient) to yield Compound 1 (40 mg).

Compound 1 (27 mg; 50 μmol) was dissolved in MeCN (1 mL) and dry 4N HClin dioxane (0.5 mL). The mixture was stirred for 10 minutes and thenconcentrated under reduced pressure to yield Compound 2 as an HCl salt,which was carried to the next step without purification.

1H-1,2,3-triazole-5-carboxylic acid (3.4 mg, 30 μmol) was combined withHATU (11 mg, 30 μmol) in DMF (0.3 mL) stirred at room temperature for 10minutes; DIPEA (1 eq.) was added and the mixture was stirred for 1minute. Compound 2 (10 mg, 30 μmol) was dissolved in DMF (0.5 mL) andDIPEA (5.2 μL, 30 μmol) was added, followed by addition of the activatedacid solution. The mixture was stirred at room temperature for 30minutes, after which time LCMS indicated desired product formation. Halfof the crude product was purified using reverse phase chromatography toyield Compound a (12.1 mg) as a TFA salt. MS m/z [M+H]⁺ calc'd forC₂₈H₃₃ClFN₅O₃, 542.23; found 542. Half of the crude product was used inthe next step without purification.

Crude Compound a (12 mg, 22 μmol) was dissolved in THF (0.3 mL), 1N LiOH(88 μL, 88 μmol) and MeOH (2 drops), and stirred for 2 hours at 50° C.AcOH (2 mL) was added and the solution was purified by reverse phasechromatography to yield Compound b (7 mg) as a TFA salt. MS m/z [M+H]⁺calc'd for C₂₆H₂₉ClFN₅O₃, 514.19; found 514.

Example 90:(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-(3,3-difluoroazetidin-1-ylmethyl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid Ethyl Ester (Compound a) and(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-(3,3-difluoroazetidin-1-ylmethyl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid (Compound b)

(2S,4S)-2-(4-Bromobenzenesulfonyloxymethyl)-4-t-butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)pentanoicacid ethyl ester (100 mg, 143 μmol) was dissolved in EtOH (3 mL),followed by addition of Na₂CO₃ (152 mg, 1.4 mmol) and3,3-difluoroazetidine (67 mg, 715 μmol). The resulting mixture wasstirred for 2 days at 70° C., at which time LCMS indicated the mass ofthe desired compound. The mixture was concentrated under reducedpressure and the crude residue was dissolved in AcOH (4 mL) and H₂O (1mL) and purified by reverse phase chromatography (10-80% MeCN/H₂Ogradient) to yield Compound 1 (8 mg).

Compound 1 (28 mg; 50 μmol) was dissolved in MeCN (1 mL) and dry 4N HClin dioxane (0.5 mL). The mixture was stirred for 10 minutes and thenconcentrated under reduced pressure to yield Compound 2 as an HCl salt,which was used in the next step without further purification.

1H-1,2,3-triazole-5-carboxylic acid (3.4 mg, 30 μmol) was combined withHATU (11 mg, 30 μmol) in DMF (0.3 mL) and stirred at room temperaturefor 10 minutes; DIPEA (1 eq.) was added and the mixture was stirred for1 minute. Compound 2 (10 mg, 30 μmol) was dissolved in DMF (0.5 mL) andDIPEA (5.2 μL, 30 μmol) was added, followed by addition of the activatedacid solution. The mixture was stirred at room temperature for 30minutes, after which time LCMS indicated desired product formation. Halfof the crude product was purified using reverse phase chromatography toyield Compound a (1.4 mg) as a TFA salt. MS m/z [M+H]⁺ calc'd forC₂₆H₂₇ClF₃N₅O₃, 550.18; found 550. Half of the crude product was used inthe next step without further purification.

Crude Compound a (12 mg, 22 μmol) was dissolved in THF (0.3 mL), 1N LiOH(88 μL, 88 μmol) and MeOH (2 drops), and stirred for 2 hours at 50° C.AcOH (1 mL) was added and the solution was purified by reverse phasechromatography to yield Compound b (0.8 mg) as a TFA salt. MS m/z [M+H]⁺calc'd for C₂₄H₂₃ClF₃N₅O₃, 522.14; found 522.

Example 91:(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-(3-fluoroazetidin-1-ylmethyl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid Ethyl Ester (Compound a) and(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-(3-fluoroazetidin-1-ylmethyl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid (Compound b)

(2S,4S)-2-(4-Bromobenzenesulfonyloxymethyl)-4-t-butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)pentanoicacid ethyl ester (100 mg, 143 μmol) was dissolved in EtOH (3 mL),followed by addition of Na₂CO₃ (152 mg, 1.4 mmol) and 3-fluoroazetidine(54 mg, 715 μmol). The resulting mixture was stirred for 2 days at 70°C., at which time LCMS indicated the mass of the desired compound. Themixture was concentrated under reduced pressure and the crude residuewas dissolved in AcOH (4 mL) and H₂O (1 mL) and purified by reversephase chromatography (10-80% MeCN/H₂O gradient) to yield Compound 1 (25mg).

Compound 1 (27 mg; 50 μmol) was dissolved in MeCN (1 mL) and dry 4N HClin dioxane (0.5 mL). The mixture was stirred for 10 minutes and thenconcentrated under reduced pressure to yield Compound 2 as an HCl salt,which was used in the next step without further purification.

1H-1,2,3-triazole-5-carboxylic acid (3.4 mg, 30 μmol) was combined withHATU (11 mg, 30 μmol) in DMF (0.3 mL) and stirred at room temperaturefor 10 minutes; DIPEA (1 eq.) was added and the mixture was stirred for1 minute. Compound 2 (10 mg, mol) was dissolved in DMF (0.5 mL) andDIPEA (5.2 μL, 30 μmol) was added, followed by addition of the activatedacid solution. The mixture was stirred at room temperature for 30minutes, after which time LCMS indicated desired product formation. Halfof the crude product was purified using reverse phase chromatography toyield Compound a (3.5 mg) as a TFA salt. MS m/z [M+H]⁺ calc'd forC₂₆H₂₈ClF₂N₅O₃, 532.19; found 532. Half of the crude product was carriedto the next step without purification.

Crude Compound a (12 mg, 22 μmol) was dissolved in THF (0.3 mL), 1N LiOH(88 μL, 88 μmol) and MeOH (2 drops), and stirred for 2 hours at 50° C.AcOH (1 mL) was added and the solution was purified by reverse phasechromatography to yield Compound b (1.2 mg) as a TFA salt. MS m/z [M+H]⁺calc'd for C₂₄H₂₄ClF₂N₅O₃, 504.15; found 504.

Example 92:(2S,4S)-2-(3,3-Bis-hydroxymethylazetidin-1-ylmethyl)-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid Ethyl Ester (Compound a) and(2S,4S)-2-(3,3-Bis-hydroxymethylazetidin-1-ylmethyl)-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid (Compound b)

(2S,4S)-2-(4-Bromobenzenesulfonyloxymethyl)-4-t-butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)pentanoicacid ethyl ester (100 mg, 143 μmol) was dissolved in EtOH (3 mL),followed by addition of Na₂CO₃ (152 mg, 1.4 mmol) and2-oxa-6-aza-spiro[3.3]heptane (71 mg, 715 μmol). The resulting mixturewas stirred for 2 days at 70° C., at which time LCMS indicated the massof the desired compound. The mixture was concentrated under reducedpressure and the crude residue was dissolved in AcOH (4 mL) and H₂O (1mL) and purified by reverse phase chromatography (10-80% MeCN/H₂Ogradient) to yield Compound 1 (20 mg).

Compound 1 (28 mg; 50 μmol) was dissolved in MeCN (1 mL) and dry 4N HClin dioxane (0.5 mL). The mixture was stirred for 10 minutes and thenconcentrated under reduced pressure to yield Compound 2 as an HCl salt,which was used in the next step without purification.

1H-1,2,3-triazole-5-carboxylic acid (3.4 mg, 30 μmol) was combined withHATU (11 mg, 30 μmol) in DMF (0.3 mL) stirred at room temperature for 10minutes; DIPEA (1 eq.) was added and the mixture was stirred for 1minute. Compound 2 (10 mg, 30 μmol) was dissolved in DMF (0.5 mL) andDIPEA (5.2 μL, 30 μmol) was added, followed by addition of the activatedacid solution. The mixture was stirred at room temperature for 30minutes, after which time LCMS indicated desired product formation. Halfof the crude product was purified using reverse phase chromatography toyield Compound a (2.9 mg) as a TFA salt. MS m/z [M+H]⁺ calc'd forC₂₈H₃₃ClFN₅O₅, 574.22; found 574. Half of the crude product was used inthe next step without purification.

Crude Compound a (12 mg, 22 μmol) was dissolved in THF (0.3 mL), 1N LiOH(88 μL, 88 μmol) and MeOH (2 drops), and stirred for 2 hours at 50° C.AcOH (1 mL) was added and the solution was purified by reverse phasechromatography to yield Compound b (1 mg) as a TFA salt. MS m/z [M+H]⁺calc'd for C₂₆H₂₉ClFN₅O₅, 546.18; found 546.

Example 93:(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-(3-hydroxymethyl-azetidin-1-ylmethyl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid Ethyl Ester (Compound a) and(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-(3-hydroxymethyl-azetidin-1-ylmethyl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid (Compound b)

(2S,4S)-2-(4-Bromobenzenesulfonyloxymethyl)-4-t-butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)pentanoicacid ethyl ester (75 mg, 107 μmol) was dissolved in EtOH (2 mL),followed by the addition of azetidin-3-yl-methanol (9.4 mg, 107 μmol).The resulting mixture was stirred at 70° C. overnight, at which timeLCMS indicated the mass of the desired compound. The organic layer wasevaporated and the residue was purified by reverse phase chromatographyto yield Compound 1 (30 mg).

Compound 1 (27 mg; 50 μmol) was dissolved in MeCN (1 mL) and dry 4N HClin dioxane (0.5 mL). The mixture was stirred for 10 minutes and thenconcentrated under reduced pressure to yield Compound 2 as an HCl salt,which was used in the next step without purification.

1H-1,2,3-triazole-5-carboxylic acid (3.4 mg, 30 μmol) was combined withHATU (11 mg, 30 μmol) in DMF (0.3 mL) and stirred at room temperaturefor 10 minutes; DIPEA (1 eq.) was added and the mixture was stirred for1 minute. Compound 2 (10 mg, 30 μmol) was dissolved in DMF (0.5 mL) andDIPEA (5.2 μL, 30 μmol) was added, followed by addition of the activatedacid solution. The mixture was stirred at room temperature for 30minutes, after which time LCMS indicated desired product formation. Halfof the crude product was purified using reverse phase chromatography toyield Compound a (20 mg) as a TFA salt. MS m/z [M+H]⁺ calc'd forC₂₇H₃₁ClFN₅O₄, 544.21; found 544. Half of the crude product was used inthe next step without purification.

Crude Compound a (12 mg, 22 μmol) was dissolved in THF (0.3 mL), 1N LiOH(88 μL, 88 μmol) and MeOH (2 drops), and stirred for 2 hours at 50° C.AcOH (1 mL) was added and the solution was purified by reverse phasechromatography to yield Compound b (10 mg) as a TFA salt. MS m/z [M+H]⁺calc'd for C₂₅H₂₇ClFN₅O₄, 516.17; found 516.

Example 94:(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-((R)-2-hydroxymethylazetidin-1-ylmethyl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid Ethyl Ester (Compound a) and(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-((R)-2-hydroxymethylazetidin-1-ylmethyl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid (Compound b)

(2S,4S)-2-(4-Bromobenzenesulfonyloxymethyl)-4-t-butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)pentanoicacid ethyl ester (75 mg, 107 μmol) was dissolved in EtOH (2 mL),followed by the addition of (2R)-2-azetidinylmethanol (18.7 mg, 215μmol). The resulting mixture was stirred at 70° C. overnight, at whichtime LCMS indicated the mass of the desired compound. The organic layerwas evaporated and the residue was purified by reverse phasechromatography to yield Compound 1 (28 mg).

Compound 1 (27 mg; 50 μmol) was dissolved in MeCN (1 mL) and dry 4N HClin dioxane (0.5 mL). The mixture was stirred for 10 minutes and thenconcentrated under reduced pressure to yield Compound 2 as an HCl salt,which was used in the next step without purification.

1H-1,2,3-triazole-5-carboxylic acid (3.4 mg, 30 μmol) was combined withHATU (11 mg, 30 μmol) in DMF (0.3 mL) stirred at room temperature for 10minutes; DIPEA (1 eq.) was added and the mixture was stirred for 1minute. Compound 2 (10 mg, 30 μmol) was dissolved in DMF (0.5 mL) andDIPEA (5.2 μL, 30 μmol) was added, followed by addition of the activatedacid solution. The mixture was stirred at room temperature for 30minutes, after which time LCMS indicated desired product formation. Halfof the crude product was purified using reverse phase chromatography toyield Compound a (5.2 mg) as a TFA salt. MS m/z [M+H]⁺ calc'd forC₂₇H₃₁ClFN₅O₄, 544.21; found 544. Half of the crude product was used inthe next step without purification.

Crude Compound a (12 mg, 22 μmol) was dissolved in THF (0.3 mL), 1N LiOH(88 μL, 88 μmol) and MeOH (2 drops), and stirred for 2 hours at 50° C.AcOH (1 mL) was added and the solution was purified by reverse phasechromatography to yield Compound b (10 mg) as a TFA salt. MS m/z [M+H]⁺calc'd for C₂₅H₂₇ClFN₅O₄, 516.17; found 516.

Example 95:(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-((S)-2-hydroxymethylazetidin-1-ylmethyl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid Ethyl Ester (Compound a) and(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-((S)-2-hydroxymethyl-azetidin-1-ylmethyl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid (Compound b)

(2S,4S)-2-(4-Bromobenzenesulfonyloxymethyl)-4-t-butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)pentanoicacid ethyl ester (75 mg, 107 μmol) was dissolved in EtOH (2 mL),followed by the addition of (2S)-2-azetidinylmethanol (9.4 mg, 107μmol). The resulting mixture was stirred at 70° C. overnight, at whichtime LCMS indicated the mass of the desired compound. The organic layerwas evaporated and the residue was purified by reverse phasechromatography to yield Compound 1 (10 mg).

Compound 1 (27 mg; 50 μmol) was dissolved in MeCN (1 mL) and dry 4N HClin dioxane (0.5 mL). The mixture was stirred for 10 minutes and thenconcentrated under reduced pressure to yield Compound 2 as an HCl salt,which was used in the next step without purification.

1H-1,2,3-triazole-5-carboxylic acid (3.4 mg, 30 μmol) was combined withHATU (11 mg, 30 μmol) in DMF (0.3 mL) and stirred at room temperaturefor 10 minutes; DIPEA (1 eq.) was added and the mixture was stirred for1 minute. Compound 2 (10 mg, mol) was dissolved in DMF (0.5 mL) andDIPEA (5.2 μL, 30 μmol) was added, followed by addition of the activatedacid solution. The mixture was stirred at room temperature for 30minutes, after which time LCMS indicated desired product formation. Halfof the crude product was purified using reverse phase chromatography toyield Compound a (4.3 mg) as a TFA salt. MS m/z [M+H]⁺ calc'd forC₂₇H₃₁ClFN₅O₄, 544.21; found 544. Half of the crude product was used inthe next step without purification.

Crude Compound a (12 mg, 22 μmol) was dissolved in THF (0.3 mL), 1N LiOH(88 μL, 88 μmol) and MeOH (2 drops), and stirred for 2 hours at 50° C.AcOH (1 mL) was added and the solution was purified by reverse phasechromatography to yield Compound b (10 mg) as a TFA salt. MS m/z [M+H]⁺calc'd for C₂₅H₂₇ClFN₅O₄, 516.17; found 516.

Example 96:(2S,4S)-2-(3-Carbamoylazetidin-1-ylmethyl)-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid Ethyl Ester (Compound a) and(2S,4S)-2-(3-Carbamoylazetidin-1-ylmethyl)-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid (Compound b)

(2S,4S)-5-(5′-Chloro-2′-fluoro-biphenyl-4-yl)-2-(3-cyanoazetidin-1-ylmethyl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicacid ethyl ester (12 mg, 22 μmol) was dissolved in THF (0.3 mL), 1N LiOH(88 μL, 88 μmol) and MeOH (2 drops), and stirred for 2 hours at 50° C.to yield a mixture of the title compounds. AcOH (1 mL) was added and thesolution was purified by reverse phase chromatography to yield Compounda (4.3 mg) as a TFA salt (MS m/z [M+H]⁺ calc'd for C₂₇H₃₀ClFN₆O₄,557.20; found 557) and Compound b (2 mg) as a TFA salt (MS m/z [M+H]⁺calc'd for C₂₅H₂₆ClFN₆O₄, 529.17; found 529).

Example 97:(2R,4R)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-(3-methoxypropylamino)-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid (Compound a) and(2R,4R)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-(3-methoxypropylamino)-4-[(1H-[1.2.3]triazole-4-carbonyl)amino]pentanoicAcid Ethyl Ester (Compound b)

(2R,4R)-4-t-Butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-hydroxy-pentanoicacid ethyl ester (137 mg, 294 μmol) was dissolved in DCM (5 mL).Methanesulfonyl chloride (23 μL, 294 μmol) was added, followed by Et₃N(82 μL, 0.6 mmol). The mixture was stirred at room temperature for 10minutes, at which time LCMS indicated the mass of the desired compound.The solvent was removed in vacuo to yield crude Compound 1, which wasused directly in the next step.

Compound 1 (53 mg, 97 μmol) was dissolved in DMF (4 mL).3-methoxypropylamine (10.9 μL, 107 μmol) and Na₂CO₃ (31.0 mg, 292 μmol)were then added, and the resulting mixture was stirred overnight at 70°C., at which time LCMS indicated the mass of the desired compound. Thesolvent was removed in vacuo and the crude residue was purified byreverse phase chromatography to yield Compound 2 (10 mg).

Compound 2 (10 mg, 19 μmol) was dissolved in MeCN (2 mL). A solution of4N HCl in dioxane (70 μL, 279 μmol) was added, and the mixture wasstirred at room temperature for 10 minutes, at which time LCMS showedreaction completion. The solvent was removed in vacuo to yield theCompound 3 as an HCl salt, which was used without further purification.

1H-1,2,3-triazole-4-carboxylic acid (2.3 mg, 20 μmol) was combined withHATU (7.7 mg, 20 μmol) in DMF (2 mL) and stirred at room temperature for15 minutes. Compound 3 (8 mg, 18 μmol) and DIPEA (9.6 μL, 55 μmol) werethen added. The solution was stirred at room temperature for 15 minutes,at which time LCMS showed reaction completion. The solvent was removedin vacuo and the crude residue was dissolved in EtOH (2 mL). A solutionof 1N LiOH (183 μL, 183 μmol) in water was added, and the resultingsolution was stirred at room temperature for 30 minutes, at which timeLCMS showed reaction completion. The solvent was removed in vacuo andthe crude residue was purified by reverse phase chromatography to yieldCompound a (3 mg) as a TFA salt. MS m/z [M+H]⁺ calc'd for C₂₄H₂₇ClFN₅O₄,504.17; found 504.

1H-1,2,3-triazole-4-carboxylic acid (3.8 mg, 34 μmol) was combined withHATU (12.9 mg, 34 μmol) in DMF (2 mL) and stirred at room temperaturefor 15 minutes. Compound 3 (60 mg, 137 μmol) and DIPEA (16 μL, 92 μmol)were then added. The solution was stirred at room temperature for 15minutes, at which time LCMS showed reaction completion. The solvent wasremoved in vacuo and the crude residue was purified by reverse phasechromatography to yield Compound b (18.5 mg) as a TFA salt. MS m/z[M+H]⁺ calc'd for C₂₆H₃₁ClFN₅O₄, 532.21; found 532.

Example 98:(2R,4R)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-(2-methoxyethylamino)-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid (Compound a) and(2R,4R)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-(2-methoxyethylamino)-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid Ethyl Ester (Compound b)

(2R,4R)-4-t-Butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-hydroxy-pentanoicacid ethyl ester (137 mg, 294 μmol) was dissolved in DCM (5 mL).Methanesulfonyl chloride (23 μL, 294 μmol) was added, followed by Et₃N(82 μL, 0.6 mmol). The mixture was stirred at room temperature for 10minutes, at which time LCMS indicated the mass of the desired compound.The solvent was removed in vacuo to yield crude Compound 1, which wasused directly in the next step.

Compound 1 (53 mg, 97 μmol) was dissolved in DMF (4 mL).2-methoxyethylamine (9.3 μL, 107 μmol) and Na₂CO₃ (31.0 mg, 292 μmol)were then added, and the resulting mixture was stirred overnight at 70°C., at which time LCMS indicated the mass of the desired compound. Thesolvent was removed in vacuo and the crude residue was purified byreverse phase chromatography to yield Compound 2 (10 mg).

Compound 2 (10 mg, 19 μmol) was dissolved in MeCN (2 mL). A solution of4N HCl in dioxane (70 μL, 279 μmol) was added, and the mixture wasstirred at room temperature for 10 minutes, at which time LCMS showedreaction completion. The solvent was removed in vacuo to yield Compound3 as an HCl salt, which was used without further purification.

1H-1,2,3-triazole-4-carboxylic acid (2.3 mg, 20 μmol) was combined withHATU (7.7 mg, 20 μmol) in DMF (2 mL) and stirred at room temperature for15 minutes. Compound 3 (7.7 mg, 18 μmol) and DIPEA (9.6 μL, 55 μmol)were then added. The solution was stirred at room temperature for 15minutes, at which time LCMS showed reaction completion. The solvent wasremoved in vacuo and the crude residue was dissolved in EtOH (2 mL). Asolution of 1N LiOH (183 μL, 183 μmol) in water was added, and theresulting solution was stirred at room temperature for 30 minutes, atwhich time LCMS showed reaction completion. The solvent was removed invacuo and the crude residue was purified by reverse phase chromatographyto yield Compound a (3 mg) as a TFA salt. MS m/z [M+H]⁺ calc'd forC₂₃H₂₅ClFN₅O₄, 490.16; found 488.

1H-1,2,3-triazole-4-carboxylic acid (3.8 mg, 34 μmol) was combined withHATU (12.9 mg, 34 μmol) in DMF (2 mL) and stirred at room temperaturefor 15 minutes. Compound 3 (13 mg, 31 μmol) and DIPEA (16 μL, 92 μmol)were then added. The solution was stirred at room temperature for 15minutes, at which time LCMS showed reaction completion. The solvent wasremoved in vacuo and the crude residue was purified by reverse phasechromatography to yield Compound b (15 mg) as a TFA salt. MS m/z [M+H]⁺calc'd for C₂₅H₂₉ClFN₅O₄, 518.19; found 518.

Example 99:(2R,4R)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-(1-isobutyryloxy-ethoxycarbonylamino)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

1H-1,2,3-triazole-5-carboxylic acid (3.4 mg, 30 μmol) and HATU (11.4 mg,30 μmol) were dissolved in DMF (0.5 mL) and stirred at room temperature.A solution of(2R,4R)-4-amino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-(1-isobutyryloxy-ethoxycarbonylamino)pentanoicacid benzyl ester (19 mg, 27 μmol) in DMF (0.5 mL) was added to thissolution, followed by DIPEA (14 μL, 82 μmol). The resulting solution wasstirred at room temperature for 90 minutes and then concentrated invacuo. The crude residue was purified by silica gel chromatography(0-100% EtOAc:hexanes) to yield Compound 1 (13 mg) as a clear oil.

Compound 1 (13 mg, 19 μmol) and palladium (10 wt % on carbon, 20.3 mg,19 μmol) were mixed in EtOAc (956 μL) and AcOH (956 μL). Hydrogen wasbubbled through the resulting solution at room temperature for 50minutes. The mixture was filtered through Celite® and the solution wasconcentrated in vacuo. The residue was diluted in a 1:1 mixture ofAcOH:H₂O (1.5 mL) and purified by preparative HPLC to yield the titlecompound (6.2 mg). MS m/z [M+H]⁺ calc'd for C₂₇H₂₉ClFN₅O₇, 590.17; found612.2; two peaks were observed in the MS trace due to the presence ofdiastereomers; note that the mass of the title compound plus the mass ofsodium (+23) was observed in the MS rather than the expected+1.

Example 100:(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-(2-dimethylamino-ethoxymethyl)-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

(2S,4S)-4-t-Butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-2-hydroxymethylpentanoicacid ethyl ester (66 mg, 138 μmol) was dissolved in dry toluene (4 mL).2-Bromo-N,N-dimethylethanamine (418 mg, 2.8 mmol), silver oxide (382 mg,1.7 mmol) and tetrabutylammonium iodide (25.4 mg, 69 μmol) were thenadded. The mixture was stirred overnight at 50° C. LC/MS showed the massof the desired product. The solids were filtered and the solvent wasremoved in vacuo. The crude residue was purified by normal phasechromatography (20-95% EtOAc/hexanes) to yield Compound 1 (109 mg).

Compound 1 (109 mg, 198 μmol) was dissolved in MeCN (4.0 mL). A solutionof 4N HCl in dioxane (742 μL, 3.0 mmol) was added. The solution wasstirred at room temperature for 15 minutes; LC/MS showed reactioncompletion. The solvent was removed in vacuo, to yield Compound 2 as anHCl salt, was used in the next step without purification.

1H-1,2,3-triazole-4-carboxylic acid (24.6 mg, 217 μmol) was combinedwith HATU (83 mg, 217 μmol) in DMF (0.3 mL) and stirred at roomtemperature for 15 minutes. Compound 2 (89 mg, 197 μmol) and DIPEA (103μL, 592 μmol) were then added. The resulting solution was stirred atroom temperature for 15 minutes; LC/MS showed the mass of the desiredproduct. The solvent was removed in vacuo and the crude residue wasdissolved in EtOH (3.0 mL). A solution of 1N LiOH in water (1.6 mL, 1.6mmol) was added, and the mixture was stirred overnight at 40° C. LC/MSshowed the mass of the desired product. The solvent was removed in vacuoand the crude residue was purified by preparative HPLC to yield thetitle compound (5 mg) as a TFA salt. MS m/z [M+H]⁺ calc'd forC₂₅H₂₉ClFN₅O₄, 518.19; found 518.2.

Example 101:(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-(3-hydroxy-3-methylazetidin-1-ylmethyl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid Ethyl Ester (Compound a),(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-(3-hydroxy-3-methylazetidin-1-ylmethyl)-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid (Compound b), and(2R,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-(3-hydroxy-3-methylazetidin-1-ylmethyl)-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid (Compound c)

(2S,4S)-2-(4-Bromobenzenesulfonyloxymethyl)-4-t-butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)pentanoicacid ethyl ester (50 mg, 72 μmol) was dissolved in EtOH (3.0 mL).3-Methyl-azetidin-3-ol (62 mg, 358 μmol) and Na₂CO₃ (76 mg, 715 μmol)were added, and the resulting mixture was stirred at 70° C. for 2 days,after which time LCMS indicated desired product formation. The solventwas removed under reduced pressure and the crude residue was purified byreverse phase chromatography (10-80% MeCN/H₂O) to yield Compound 1 (40mg).

Compound 1 (16 mg) was combined with MeCN (1 mL) and 4 N HCl in dioxane(0.5 mL) and stirred for 10 minutes. The solvent was removed underreduced pressure to yield Compound 2 as an HCl salt, which was useddirectly in the next step.

3H-1,2,3-triazole-4-carboxylic acid (3.4 mg, 30 μmol) was combined withHATU (11 mg, 30 μmol) in DMF (0.3 mL) and stirred at room temperaturefor 10 minutes; DIPEA (1 eq.) was added and the mixture was stirred for1 minute. Compound 2 (10 mg, 30 μmol) in DMF (0.5 mL) was combined withDIPEA (5.2 μL, 30 μmol), then added to the activated acid solution. Theresulting solution was stirred at room temperature for 30 minutes; LC/MSshowed the mass of the desired product. The solvent was removed in vacuoand the crude residue was purified by reverse phase chromatography toyield Compound a (6.1 mg) as a TFA salt. MS m/z [M+H]⁺ calc'd forC₂₇H₃₁ClFN₅O₄, 544.21; found 545.2.

Compound a (12 mg, 22 μmol) was combined with THF (0.3 mL), 1N LiOH (88μL, 88 μmol) and 2 drops of MeOH. The resulting mixture was stirred for2 hours at 50° C.; LC/MS showed the mass of the desired product. Thesolution was then purified by reverse phase chromatography to yieldCompound b as a TFA salt. MS m/z [M+H]⁺ calc'd for C₂₅H₂₇ClFN₅O₄,516.17; found 516.

Compound c was prepared in a similar manner using the appropriatestarting materials. MS m/z [M+H]⁺ calc'd for C₂₅H₂₇ClFN₅O₄, 516.17;found 516.

Example 102:(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-(3-methoxy-azetidin-1-ylmethyl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid Ethyl Ester (Compound a),(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-(3-methoxyazetidin-1-ylmethyl)-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid (Compound b), and(2R,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-(3-methoxyazetidin-1-ylmethyl)-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid (Compound c)

(2S,4S)-2-(4-Bromobenzenesulfonyloxymethyl)-4-t-butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)pentanoicacid ethyl ester (50 mg, 72 μmol) was dissolved in EtOH (3.0 mL).3-Methoxy-azetidine (62 mg, 358 μmol) and Na₂CO₃ (76 mg, 715 μmol) wereadded, and the resulting mixture was stirred at 70° C. for 2 days, afterwhich time LCMS indicated desired product formation. The solvent wasremoved under reduced pressure and the crude residue was purified byreverse phase chromatography (10-80% MeCN/H₂O) to yield Compound 1 (8mg).

Compound 1 (16 mg) was combined with MeCN (1 mL) and 4 N HCl in dioxane(0.5 mL) and stirred for 10 minutes. The solvent was removed underreduced pressure to yield Compound 2 as an HCl salt, which was useddirectly in the next step.

3H-1,2,3-triazole-4-carboxylic acid (3.4 mg, 30 μmol) was combined withHATU (11 mg, 30 μmol) in DMF (0.3 mL) and stirred at room temperaturefor 10 minutes; DIPEA (1 eq.) was added and the mixture was stirred for1 minute. Compound 2 (10 mg, 30 μmol) in DMF (0.5 mL) was combined withDIPEA (5.2 μL, 30 μmol), then added to the activated acid solution. Theresulting solution was stirred at room temperature for 30 minutes; LC/MSshowed the mass of the desired product. The solvent was removed in vacuoand the crude residue was purified by reverse phase chromatography toyield Compound a (8.5 mg) as a TFA salt. MS m/z [M+H]⁺ calc'd forC₂₇H₃₁ClFN₅O₄, 544.21; found 545.2.

Compound a (12 mg, 22 μmol) was combined with THF (0.3 mL), 1N LiOH (88μL, 88 μmol) and 2 drops of MeOH. The resulting mixture was stirred for2 hours at 50° C.; LC/MS showed the mass of the desired product. Thesolution was then purified by reverse phase chromatography to yieldCompound b as a TFA salt. MS m/z [M+H]⁺ calc'd for C₂₅H₂₇ClFN₅O₄,516.17; found 516.

Compound c was prepared in a similar manner using the appropriatestarting materials. MS m/z [M+H]⁺ calc'd for C₂₅H₂₇ClFN₅O₄, 516.17;found 516.

Example 103:(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-((R)-2-methoxymethylazetidin-1-ylmethyl)-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid Ethyl Ester (Compound a),(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-((R)-2-methoxymethylazetidin-1-ylmethyl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid (Compound b),(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-((S)-2-methoxymethylazetidin-1-ylmethyl)-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid Ethyl Ester (Compound c), and(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-((S)-2-methoxymethylazetidin-1-ylmethyl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid (Compound d)

(2S,4S)-2-(4-Bromobenzenesulfonyloxymethyl)-4-t-butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)pentanoicacid ethyl ester (80 mg, 114 μmol) was dissolved in EtOH (3.0 mL).(R)-2-(methoxymethyl)azetidine (34.7 mg, 343 μmol) and Na₂CO₃ (121 mg,1.1 mmol) were added, and the resulting mixture was stirred at 70° C.overnight, after which time LCMS indicated desired product formation.The solvent was removed in vacuo and the crude residue was purified byreverse phase chromatography (26.4 mg). The residue was dissolved inMeCN (3.0 mL). A solution of 4N HCl in dioxane (653 μL, 2.6 mmol) wasadded, and the resulting solution was stirred at room temperature for 20minutes, after which time LCMS indicated desired product formation. Thesolvent was removed in vacuo to yield Compound 1 as an HCl salt.

1H-1,2,3-triazole-4-carboxylic acid (9.8 mg, 87 μmol) and HATU (36.4 mg,96 μmol) were combined in DMF (3.0 mL) and stirred at room temperaturefor 15 minutes. Compound 1 (40.3 mg, 87 μmol) and DIPEA (46 μL, 261μmol) were added and the resulting solution was stirred at roomtemperature for 15 minutes, after which time LCMS indicated desiredproduct formation. The solvent was removed in vacuo and the cruderesidue was purified by reverse phase chromatography to yield Compound a(5.2 mg) as a TFA salt. MS m/z [M+H]⁺ calc'd for C₂₈H₃₃ClFN₅O₄, 558.22;found 558.

Compound a (5.2 mg, 9.3 μmol) was dissolved in EtOH (3.0 mL). A solutionof 1N LiOH (75 μL, 75 μmol) in water was added, and the resultingsolution was stirred at room temperature overnight, after which timeLCMS indicated desired product formation. The solvent was removed invacuo and the crude residue was purified by reverse phase chromatographyto yield Compound b (4.0 mg) as a TFA salt. MS m/z [M+H]⁺ calc'd forC₂₆H₂₉ClFN₅O₄, 530.19; found 530.

(2S,4S)-2-(4-Bromobenzenesulfonyloxymethyl)-4-t-butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)pentanoicacid ethyl ester (80 mg, 114 μmol) was dissolved in EtOH (3.0 mL).(S)-2-(methoxymethyl)azetidine (34.7 mg, 343 μmol) and Na₂CO₃ (121 mg,1.1 mmol) were added, and the resulting mixture was stirred at 70° C.overnight, after which time LCMS indicated desired product formation.The solvent was removed in vacuo and the crude residue was purified byreverse phase chromatography (49 mg). The residue was dissolved in MeCN(3.0 mL). A solution of 4N HCl in dioxane (653 μL, 2.6 mmol) was added,and the resulting solution was stirred at room temperature for 20minutes, after which time LCMS indicated desired product formation. Thesolvent was removed in vacuo to yield Compound 2 as an HCl salt.

1H-1,2,3-triazole-4-carboxylic acid (9.8 mg, 87 μmol) and HATU (36.4 mg,96 μmol) were combined in DMF (3.0 mL) and stirred at room temperaturefor 15 minutes. Compound 2 (40.3 mg, 87 μmol) and DIPEA (46 μL, 261μmol) were added and the resulting solution was stirred at roomtemperature for 15 minutes, after which time LCMS indicated desiredproduct formation. The solvent was removed in vacuo and the cruderesidue was purified by reverse phase chromatography to yield Compound c(34.5 mg) as a TFA salt. MS m/z [M+H]⁺ calc'd for C₂₈H₃₃ClFN₅O₄, 558.22;found 558.

Compound c (26 mg, 47 μmol) was dissolved in EtOH (3.0 mL). A solutionof 1N LiOH (75 μL, 75 μmol) in water was added, and the resultingsolution was stirred at room temperature overnight, after which timeLCMS indicated desired product formation. The solvent was removed invacuo and the crude residue was purified by reverse phase chromatographyto yield Compound d (15 mg) as a TFA salt. MS m/z [M+H]⁺ calc'd forC₂₆H₂₉ClFN₅O₄, 530.19; found 530.

Example 104:(2S,4S)-2-(1-Amino-1-methylethyl)-5-(5′-chloro-2′-fluorobiphenyl-4-yl)-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

1H-1,2,3-triazole-5-carboxylic acid (15.3 mg, 135 μmol) and HATU (51.4mg, 135 μmol) were mixed in DMF (4 mL) and stirred at room temperaturefor 15 minutes.(2S,4S)-4-Amino-2-(1-amino-1-methylethyl)-5-(5′-chloro-2′-fluorobiphenyl-4-yl)pentanoicacid ethyl ester (50 mg, 123 μmol) and DIPEA (64 μL, 369 μmol) wereadded. The resulting solution was stirred at room temperature for 15minutes, at which point LC/MS showed reaction completion. The solventwas removed in vacuo and the crude residue was diluted in EtOH (4 mL). Asolution of 1N LiOH (983 μL, 983 μmol) in water was then added. Theresulting solution was stirred at 60° C. for 2 days, at which pointLC/MS showed reaction completion. The solvent was removed in vacuo andthe crude residue was purified by preparative HPLC to yield the titlecompound (4.2 mg) as a TFA salt. MS m/z [M+H]⁺ calc'd for C₂₃H₂₅ClFN₅O₃,474.16; found 474.2.

Example 105:(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-[3-(2-hydroxyethyl)azetidin-1-ylmethyl]-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

(2S,4S)-2-(4-Bromobenzenesulfonyloxymethyl)-4-t-butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)pentanoicacid ethyl ester (60 mg, 86 μmol) was dissolved in EtOH (3.0 mL).2-(Azetidin-3-yl)ethan-1-ol HCl (26.0 mg, 258 μmol) and Na₂CO₃ (91 mg,858 μmol) were added, and the resulting mixture was stirred at 70° C.overnight, after which time LCMS indicated desired product formation.The solvent was removed in vacuo and the crude residue was purified byreverse phase chromatography (60 mg). The residue (60 mg, 107 μmol) wasdissolved in MeCN (3.0 mL). A solution of 4N HCl in dioxane (653 μL, 2.6mmol) was added, and the resulting solution was stirred at roomtemperature for 20 minutes, after which time LCMS indicated desiredproduct formation. The solvent was removed in vacuo to yield Compound 1as an HCl salt.

1H-1,2,3-triazole-4-carboxylic acid (9.8 mg, 87 μmol) and HATU (36.4 mg,96 μmol) were combined in DMF (3.0 mL) and stirred at room temperaturefor 15 minutes. Compound 1 (49.3 mg, 106 μmol) and DIPEA (46 μL, 261μmol) were added and the resulting solution was stirred at roomtemperature for 15 minutes, after which time LCMS indicated desiredproduct formation. The solvent was removed in vacuo and the cruderesidue was purified by reverse phase chromatography.

The residue (56.8 mg, 87 μmol) was dissolved in EtOH (3.0 mL). Asolution of 1N LiOH (696 μL, 696 μmol) in water was added, and theresulting solution was stirred at room temperature overnight, afterwhich time LCMS indicated desired product formation. The solvent wasremoved in vacuo and the crude residue was purified by reverse phasechromatography to yield the title compound (36 mg) as a TFA salt. MS m/z[M+H]⁺ calc'd for C₂₆H₂₉ClFN₅O₄, 530.19; found 530.

Example 106:(2S,4S)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-{[(2-hydroxyethyl)-methylamino]methyl}-4-[(1H-[1,2,3]triazole-4-carbonyl)amino]pentanoicAcid

(2S,4S)-2-(4-Bromobenzenesulfonyloxymethyl)-4-t-butoxycarbonylamino-5-(5′-chloro-2′-fluorobiphenyl-4-yl)pentanoicacid ethyl ester (50 mg, 72 μmol) was dissolved in EtOH (2 mL).2-methoxy-N-methylethanamine (19.1 mg, 215 μmol) was added and theresulting mixture was stirred at 50° C. for 2 days, after which timeLCMS indicated desired product formation. The organic layer wasevaporated and the crude residue was purified by reverse phasechromatography to yield Compound 1 (20 mg).

Compound 1 (15 mg, 28 μmol) was combined with MeCN (0.5 mL) and dry 4NHCl in dioxane (0.3 mL) and stirred for 10 minutes. The solvent wasremoved under reduced pressure to yield crude Compound 2, which was useddirectly in the next step.

1H-1,2,3-triazole-5-carboxylic acid (3.1 mg, 27 μmol) was combined withHATU (10.4 mg, 27 μmol) in DMF (0.5 mL), and stirred for 10 minutes.DIPEA (4.8 μL, 27 Mmol) was added and the resulting mixture was stirredfor 1 minute. Compound 2 (12 mg, 27 μmol) dissolved in DMF (1 mL) wascombined with added DIPEA (14.4 μL, 82 μmol) followed by addition of theactivated acid solution. The resulting mixture was stirred for 30minutes then purified by reverse phase chromatography (0-100%EtOAc/hexanes to yield Compound 3 (10 mg).

Compound 3 (9.0 mg, 17 μmol) was combined with 1N LiOH (84 μL, 84 μmol),THF (0.5 mL), and MeOH (0.1 mL). The mixture was stirred at roomtemperature for 1 hour, then purified by reverse phase chromatography toyield the title compound (1 mg) as a TFA salt. MS m/z [M+H]⁺ calc'd forC₂₄H₂₇ClFN₅O₄, 504.17; found 504.

Assay 1: In Vitro Assays for the Quantitation of Inhibitor Potencies atHuman and Rat NEP, and Human ACE

The inhibitory activities of compounds at human and rat neprilysin (EC3.4.24.11; NEP) and human angiotensin converting enzyme (ACE) weredetermined using in vitro assays as described below.

Extraction of NEP Activity from Rat Kidneys

Rat NEP was prepared from the kidneys of adult Sprague Dawley rats.Whole kidneys were washed in cold phosphate buffered saline (PBS) andbrought up in ice-cold lysis buffer (1% Triton X-114, 150 mM NaCl, 50 mMtris(hydroxymethyl) aminomethane (Tris) pH 7.5; Bordier (1981) J. Biol.Chem. 256: 1604-1607) in a ratio of 5 mL of buffer for every gram ofkidney. Samples were homogenized on ice using a polytron hand heldtissue grinder. Homogenates were centrifuged at 1000×g in a swingingbucket rotor for 5 minutes at 3° C. The pellet was resuspended in 20 mLof ice cold lysis buffer and incubated on ice for 30 minutes. Samples(15-20 mL) were then layered onto 25 mL of ice-cold cushion buffer (6%w/v sucrose, 50 mM pH 7.5 Tris, 150 mM NaCl, 0.06%, Triton X-114),heated to 37° C. for 3-5 minutes and centrifuged at 1000×g in a swingingbucket rotor at room temperature for 3 minutes. The two upper layerswere aspirated off, leaving a viscous oily precipitate containing theenriched membrane fraction. Glycerol was added to a concentration of 50%and samples were stored at −20° C. Protein concentrations werequantitated using a BCA detection system with bovine serum albumin (BSA)as a standard.

Enzyme Inhibition Assays

Recombinant human NEP and recombinant human ACE were obtainedcommercially (R&D Systems, Minneapolis, Minn., catalog numbers 1182-ZNand 929-ZN, respectively). The fluorogenic peptide substrateMca-D-Arg-Arg-Leu-Dap-(Dnp)-OH (Medeiros et al. (1997) Braz. J. Med.Biol. Res. 30:1157-62; Anaspec, San Jose, Calif.) andAbz-Phe-Arg-Lys(Dnp)-Pro-OH (Araujo et al. (2000) Biochemistry39:8519-8525; Bachem, Torrance, Calif.) were used in the NEP and ACEassays respectively.

The assays were performed in 384-well white opaque plates at 37° C.using the fluorogenic peptide substrates at a concentration of 10 μM inAssay Buffer (NEP: 50 mM HEPES, pH 7.5, 100 mM NaCl, 0.01% polyethyleneglycol sorbitan monolaurate (Tween-20), 10 μM ZnSO₄; ACE: 50 mM HEPES,pH 7.5, 100 mM NaCl, 0.01% Tween-20, 1 μM ZnSO₄). The respective enzymeswere used at concentrations that resulted in quantitative proteolysis of1 μM of substrate after 20 minutes at 37° C.

Test compounds were assayed over the range of concentrations from 10 μMto 20 μM. Test compounds were added to the enzymes and incubated for 30minute at 37° C. prior to initiating the reaction by the addition ofsubstrate. Reactions were terminated after 20 minutes of incubation at37° C. by the addition of glacial acetic acid to a final concentrationof 3.6% (v/v).

Plates were read on a fluorometer with excitation and emissionwavelengths set to 320 nm and 405 nm, respectively. Inhibition constantswere obtained by nonlinear regression of the data using the equation(GraphPad Software, Inc., San Diego, Calif.):v=v ₀/[1+(I/K′)]where v is the reaction rate, v₀ is the uninhibited reaction rate, I isthe inhibitor concentration and K′ is the apparent inhibition constant.

Compounds of the invention were tested in this assay and found to havepK_(i) values at human NEP as follows. In some instances, prodrugcompounds did not inhibit the enzyme in this in vitro assay, or theprodrugs (the term “prodrug” is intended to mean an inactive orsignificantly less active precursor of a drug that is converted into itsactive form in the body under physiological conditions, for example, bynormal metabolic processes; such compounds may not necessarily possesspharmacological activity at NEP, but may be administered orally orparenterally and thereafter metabolized in the body to form compoundsthat are pharmacologically active at NEP) were not tested (n.d.) sinceactivity would not be expected.

Ex. pK_(i)  1 ≥9.0 2-1 ≥9.0 2-2 ≥9.0 2-3 8.5-8.9 2-4 ≥9.0 2-5 ≥9.0 2-6≥9.0 2-7 ≥9.0 2-8 ≥9.0 2-9 ≥9.0  2-10 8.5-8.9  2-11 ≥9.0  2-12 ≥9.0 2-13 ≥9.0  2-14 ≥9.0  2-15 ≥9.0  2-16 ≥9.0  3 ≥9.0 4-1 ≥9.0 4-2 ≥9.04-3 ≥9.0  5 ≥9.0  6 ≥9.0 7-1 ≥9.0 7-2 ≥9.0 7-3 ≥9.0 7-4 ≥9.0 7-5 ≥9.07-6 ≥9.0 7-7 8.5-8.9 7-8 8.5-8.9 7-9 ≥9.0  7-10 ≥9.0  7-11 ≥9.0  8 ≥9.09-1 ≥9.0 9-2 ≥9.0 9-3 ≥9.0 9-4 ≥9.0 9-5 ≥9.0 10 ≥9.0 11 8.5-8.9 128.5-8.9 13 ≥9.0  14a 7.5-8.0  14b 7.0-7.5 15 ≥9.0 16-1  8.5-8.9 16-2 8.5-8.9 16-3  8.5-8.9 16-4  8.5-8.9 16-5  8.0-8.5 16-6  8.0-8.5 16-7 8.0-8.5 16-8  8.0-8.5 16-9  ≥9.0 16-10 7.5-8.0 16-11 8.0-8.5 16-12 n.d.16-13 n.d. 16-14 n.d. 16-15 8.0-8.5 16-16 ≥9.0 16-17 n.d. 16-18 ≥9.016-19 n.d. 16-20 8.5-8.9 16-21 ≥9.0 16-22 n.d. 16-23 ≥9.0 16-24 ≥9.016-25 ≥9.0 16-26 8.5-8.9 16-27 8.5-8.9 16-28 ≥9.0 16-29 ≥9.0 16-30 n.d.16-31 ≥9.0 16-32 n.d. 16-33 ≥9.0 16-34 n.d. 16-35 ≥9.0 16-36 n.d. 17≥9.0 18-1  8.0-8.5 18-2  ≥9.0 18-3  ≥9.0 18-4  8.0-8.5 18-5  8.5-8.918-6  ≥9.0 18-7  7.5-8.0 18-8  ≥9.0 18-9  8.0-8.5 18-10 ≥9.0 18-11 ≥9.018-12 8.0-8.5 19 n.d. 20 ≥9.0 21-1  ≥9.0 21-2  8.5-8.9 21-3  ≥9.0 21-4 8.5-8.9 21-5  8.5-8.9 21-6  8.5-8.9 21-7  8.5-8.9 21-8  n.d. 21-9  n.d.21-10 n.d. 22 8.5-8.9 23 8.5-8.9 24-1  8.0-8.5 24-2  8.5-8.9 25 8.0-8.526 8.0-8.5 27 8.0-8.5 28 ≥9.0 29 ≥9.0 30-1  ≥9.0 30-2  ≥9.0 30-3  ≥9.030-4  ≥9.0 30-5  ≥9.0 30-6  ≥9.0 30-7  ≥9.0 30-8  8.5-8.9 30-9  ≥9.030-10 ≥9.0 30-11 ≥9.0 30-12 ≥9.0 31 8.5-8.9 32 8.0-8.5 33 ≥9.0 34-1 8.5-8.9 35 8.0-8.5 36-1  8.5-8.9 36-2  8.5-8.9 37-1  ≥9.0 38-1  8.0-8.538-2  8.5-8.9 39-1  ≥9.0 40 ≥9.0 41 ≥9.0 42-1  8.5-8.9 42-2  8.5-8.9 43≥9.0 44-1  ≥9.0 44-2  n.d. 45 ≥9.0 46 8.5-8.9 47 8.0-8.5  48a ≥9.0  48b8.5-8.9  48c n.d.  49a ≥9.0  49b ≥9.0  49c n.d. 50 ≥9.0 51 8.5-8.9 52-1 ≥9.0 52-2  8.0-8.5 52-3  8.5-8.9 53 ≥9.0 54 8.5-8.9 55 8.0-8.5 568.5-8.9 57 ≥9.0 58 8.0-8.5 59 ≥9.0 60 8.0-8.5  61a ≥9.0  61b ≥9.0 62≥9.0 63 8.5-8.9 64 8.5-8.9 65 8.5-8.9 66 8.5-8.9 67 ≥9.0 68 8.0-8.5  69a8.5-8.9  69b n.d. 70 ≥9.0 71 ≥9.0 72 ≥9.0 73 ≥9.0 74 8.5-8.9 75 8.5-8.976 7.5-7.9  77a 8.0-8.5  77b 8.0-8.5 78 8.5-8.9 79 8.5-8.9 80 ≥9.0 818.0-8.5  82a ≥9.0  82b n.d.  83a n.d.  83b ≥9.0  84a n.d.  84b ≥9.0  85a≥9.0  85b n.d. 86 n.d.  87a n.d.  87b ≥9.0  88a n.d.  88b ≥9.0  89a n.d. 89b ≥9.0  90a n.d.  90b ≥9.0  91a n.d.  91b ≥9.0  92a n.d.  92b ≥9.0 93a n.d.  93b ≥9.0  94a n.d.  94b ≥9.0  95a n.d.  95b ≥9.0  96a n.d. 96b ≥9.0  97a ≥9.0  97b n.d.  98a ≥9.0  98b n.d. 99 n.d. 100  ≥9.0 101an.d. 101b ≥9.0 101c 8.5-8.9 102a n.d. 102b ≥9.0 102c ≥9.0 103a n.d. 103b≥9.0 103c n.d. 103d ≥9.0 104  ≥9.0 105  ≥9.0 106  8.5-8.9

Assay 2: Pharmacodynamic (PD) Assay for ACE and NEP Activity inAnesthetized Rats

Male, Sprague Dawley, normotensive rats are anesthetized with 120 mg/kg(i.p.) of inactin. Once anesthetized, the jugular vein, carotid artery(PE 50 tubing) and bladder (flared PE 50 tubing) catheters arecannulated and a tracheotomy is performed (Teflon Needle, size 14 gauge)to facilitate spontaneous respiration. The animals are then allowed a 60minute stabilization period and kept continuously infused with 5 mL/kg/hof saline (0.9%) throughout, to keep them hydrated and ensure urineproduction. Body temperature is maintained throughout the experiment byuse of a heating pad. At the end of the 60 minute stabilization period,the animals are dosed intravenously (i.v.) with two doses of AngI (1.0μg/kg, for ACE inhibitor activity) at 15 minutes apart. At 15 minutespost-second dose of AngI, the animals are treated with vehicle or testcompound. Five minutes later, the animals are additionally treated witha bolus i.v. injection of atrial natriuretic peptide (ANP; 30 μg/kg).Urine collection (into pre-weighted eppendorf tubes) is startedimmediately after the ANP treatment and continued for 60 minutes. At 30and 60 minutes into urine collection, the animals are re-challenged withAngI. Blood pressure measurements are done using the Notocord system(Kalamazoo, Mich.). Urine samples are frozen at −20° C. until used forthe cGMP assay. Urine cGMP concentrations are determined by EnzymeImmuno Assay using a commercial kit (Assay Designs, Ann Arbor, Mich.,Cat. No. 901-013). Urine volume is determined gravimetrically. UrinarycGMP output is calculated as the product of urine output and urine cGMPconcentration. ACE inhibition is assessed by quantifying the %inhibition of pressor response to AngI. NEP inhibition is assessed byquantifying the potentiation of ANP-induced elevation in urinary cGMPoutput.

Assay 3: In Vivo Evaluation of Antihypertensive Effects in the ConsciousSHR Model of Hypertension

Spontaneously hypertensive rats (SHR, 14-20 weeks of age) are allowed aminimum of 48 hours acclimation upon arrival at the testing site withfree access to food and water. For blood pressure recording, theseanimals are surgically implanted with small rodent radiotransmitters(telemetry unit; DSI Models TA 11PA-C40 or C50-PXT, Data Science Inc.,USA). The tip of the catheter connected to the transmitter is insertedinto the descending aorta above the iliac bifurcation and secured inplace with tissue adhesive. The transmitter is kept intraperitoneallyand secured to the abdominal wall while closing of the abdominalincision with a non-absorbable suture. The outer skin is closed withsuture and staples. The animals are allowed to recover with appropriatepost-operative care. On the day of the experiment, the animals in theircages are placed on top of the telemetry receiver units to acclimate tothe testing environment and baseline recording. After at least of 2hours baseline measurement is taken, the animals are then dosed withvehicle or test compound and followed out to 24 hours post-dose bloodpressure measurement. Data is recorded continuously for the duration ofthe study using Notocord software (Kalamazoo, Mich.) and stored aselectronic digital signals. Parameters measured are blood pressure(systolic, diastolic and mean arterial pressure) and heart rate.

Assay 4: In Vivo Evaluation of Antihypertensive Effects in the ConsciousDOCA-Salt Rat Model of Hypertension

CD rats (male, adult, 200-300 grams, Charles River Laboratory, USA) areallowed a minimum of 48 hours acclimation upon arrival at the testingsite before they are placed on a high salt diet. One week after thestart of the high salt diet (8% in food or 1% NaCl in drinking water), adeoxycorticosterone acetate (DOCA) pellet (100 mg, 90 days release time,Innovative Research of America, Sarasota, Fla.) is implantedsubcutaneously and unilateral nephrectomy is performed. At this time,the animals are also surgically implanted with small rodentradiotransmitters for blood pressure measurement (see Assay 3 fordetails). The animals are allowed to recover with appropriatepost-operative care. Study design, data recording, and parametersmeasured is similar to that described for Assay 3.

Assay 5: In Vivo Evaluation of Antihypertensive Effects in the ConsciousDahl/SS Rat Model of Hypertension

Male, Dahl salt sensitive rats (Dahl/SS, 6-7 weeks of age from CharlesRiver Laboratory, USA) are allowed at least 48 hours of acclimation uponarrival at the testing site before they were placed on a 8% NaCl highsalt diet (TD.92012, Harlan, USA) then surgically implanted with smallrodent radiotransmitters for blood pressure measurement (see Assay 3 fordetails). The animals are allowed to recover with appropriatepost-operative care. At approximately 4 to 5 weeks from the start ofhigh salt diet, these animals are expected to become hypertensive. Oncethe hypertension level is confirmed, these animals are used for thestudy while continued with the high salt diet to maintain theirhypertension level. Study design, data recording, and parametersmeasured is similar to that described in Assay 3.

Assay 6: Rat PO Cassette Assay

Oral bioavailability, or % F, is a measure of the percentage of a drugin an oral dose that actually reaches the systemic circulation. Compoundlosses can occur due to incomplete formulation dissolution, incompleteabsorption due to compound insolubility or instability along the GI, ormetabolism in the gut or across the gut wall. The fraction of the dosewhich reaches the hepatic portal vein must also then pass through theliver before reaching the systemic circulation. Compound metabolism, or“first-pass extraction,” can occur during this initial passage throughthe liver, and this is an additional potential source of compound loss.Oral bioavailability is calculated as the dose-normalized ratio of drugexposure after an oral dose to that after an intravenous dose, whereinthe entire dose is delivered directly to the systemic circulation.

Each cassette study begins with 10 mM DMSO stock solutions of up to 5different compounds. Typically, compounds are selected such no twocompounds dosed in the same cassette have a molecular weight within 5 Daof each other. This simplifies subsequent bioanalysis. Appropriatevolumes of each DMSO stock are added into a volume of vehicle (5% sodiumbicarbonate, 5% dextrose in H₂O) such that the final concentration ofeach compound is 0.25 mg/mL. Intravenous dosing solutions aresterile-filtered (0.2 μm) prior to dosing.

Pre-cannulated male Sprague-Dawley rats (3 per cassette per route)between 8 and 10 weeks of age were obtained from Harlan Laboratories(Indianapolis, Ind.). Rats received either a single oral gavage or asingle intravenous (via lateral tail vein) dose (2 mL/kg) of the dosingsolution. The final dose was 0.5 mg/kg. Serial blood samples wereharvested via jugular vein cannula at 3 minutes, 15 minutes, 30 minutes,1 hours, 2 hours, 4 hours, 6 hours, and 24 hours post-dose. Sampling wasperformed either manually or using automated blood samplers. Sampleswere collected into microtainer tubes containing EDTA as theanticoagulant and are processed to plasma by refrigeratedcentrifugation.

Plasma samples were extracted with 3 volumes of MeCN containing asuitable internal standard. Extracts were reconstituted into 3 volumesof water containing 1% formic acid, and analyzed via HPLC-coupled MS/MS.Plasma concentration-time data were analyzed using the Phoenix software(Pharsight Corp., St. Louis, Mo.) to calculate pharmacokineticparameters.

Compounds of the invention of particular interest were those having a %F>10%, when tested in this assay. These include the following compounds:

Example 1 2-1 2-2 2-6 2-8 2-9  2-13  2-15  2-16 3 5 7-1 7-2 7-4 14a 14b16-10 16-23 16-24 16-32 21-1  29  30-4  30-6  30-12 52-1  69b 84a 91a

While the present invention has been described with reference tospecific aspects or embodiments thereof, it will be understood by thoseof ordinary skilled in the art that various changes can be made orequivalents can be substituted without departing from the true spiritand scope of the invention. Additionally, to the extent permitted byapplicable patent statutes and regulations, all publications, patents,and patent applications cited herein are hereby incorporated byreference in their entirety to the same extent as if each document hadbeen individually incorporated by reference herein.

What is claimed is:
 1. A process for preparing a compound of Formula I:

or a pharmaceutically acceptable salt thereof, wherein: R¹ is H,—C₁₋₈alkyl, —CH(CH₃)OC(O)—O-cyclohexyl, —(CH₂)₂-morpholinyl, or—CH₂-5-methyl-[1,3]dioxol-2-one; R² is —C₀₋₃alkylene-NR²²R²³; R²² is Hor —C₁₋₆alkyl R²³ is H, —C₁₋₆alkyl, —C₁₋₆alkyl substituted with 1 to 6fluoro atoms, —SO₂—C₁₋₆alkyl, —CH₂OC(O)—C₁₋₆alkyl, —C₂₋₄alkylene-OH,—C₂₋₄alkylene-O—CH₃, or cyclopropyl optionally substituted with one ortwo R³¹ groups; or R²² and R²³ are taken together to form—(CH₂)₂—O—(CH₂)₂—, a 2-oxa-6-aza-spiro[3.3]heptane ring, or an azetidinering optionally substituted with one or two R³¹ groups; and each R³¹ isindependently halo, —C₁₋₆alkyl, —C₀₋₂alkylene-OH,—C₀₋₂alkylene-OC₁₋₆alkyl, —CN, or —CONH₂; R³, R⁴ and R⁵ areindependently H or halo; and R⁶ is a heterocycle selected from the groupconsisting of 3H-oxazol-2-one, [1,2,4]oxadiazol-5-one,[1,2,3,5]oxatriazole, dihydro-[1,2,4]triazol-3-one,[1,2,4]triazolo[1,5-α]pyridine, triazole, pyrazole, imidazole, oxazole,isoxazole, isothiazole, pyridine, oxadiazole, and pyrimidine; whereinthe heterocycle is attached at a carbon atom; and each nitrogen atom inthe heterocycle is unsubstituted or substituted with an R⁶⁰ groupselected from the group consisting of —OH, —(CH₂)₂OH,—C₀₋₂alkylene-O—C₁₋₆alkyl, —C₁₋₆alkyl, —CHF₂, —CF₃, and phenyl; and eachcarbon atom in the heterocycle is unsubstituted or substituted with anR⁶¹ group independently selected from the group consisting of halo, —OH,—C₁₋₆alkyl, —C₀₋₂alkylene-O—C₁₋₆alkyl, —C(O)CH₃, —C(O)NH(CH₃),—C(O)N(CH₃)₂, —C₃₋₆cycloalkyl, —CF₃, —CH₂SO₂CH₃, —NH₂, —CH₂NH₂,—CH₂N(CH₃)₂, pyrazine, and phenyl substituted with methyl or halo;comprising the step of coupling a compound of formula 1 with a compoundof formula 2:

to produce a compound of formula I, or a pharmaceutically acceptablesalt thereof, wherein P¹ is H or an amino-protecting group selected fromthe group consisting of t-butoxycarbonyl, trityl, benzyloxycarbonyl,9-fluorenylmethoxycarbonyl, formyl, trimethylsilyl, andt-butyldimethylsilyl; and wherein the process further comprisesdeprotecting the compound of formula 1 when P¹ is an amino protectinggroup.